Add real AKShare NAV-date probe slice (3d-12)

13 files changed, 675 insertions, 16 deletions

diff --git a/qa/driver/browser-test.js b/qa/driver/browser-test.js
index c7ee468..76fa69b 100644
--- a/qa/driver/browser-test.js
+++ b/qa/driver/browser-test.js
@@ -32,6 +32,7 @@ let lastRebalancePlansResponse = null;
 let lastRebalancePreviewResponse = null;
 let lastRebalanceExecuteResponse = null;
 let lastRebalanceExecutionsResponse = null;
+let lastNavDatesResponse = null;
 
 function check(name, ok, detail) {
   results.push({ name, ok, detail: detail || "" });
@@ -171,7 +172,12 @@ async function summaryLabelExists(page, label, name) {
         lastRebalanceExecutionsResponse = await r.json();
       } catch {}
     }
-    if (r.status() >= 400 && !/\/api\/instruments\//.test(r.url()) && !/\/orders/.test(r.url()) && !/\/redemptions/.test(r.url()) && !/\/capital/.test(r.url())) {
+    if (r.url().includes("/market/nav-dates") && r.request().method() === "GET" && r.status() < 400) {
+      try {
+        lastNavDatesResponse = await r.json();
+      } catch {}
+    }
+    if (r.status() >= 400 && !/\/api\/instruments\//.test(r.url()) && !/\/api\/market\//.test(r.url()) && !/\/orders/.test(r.url()) && !/\/redemptions/.test(r.url()) && !/\/capital/.test(r.url())) {
       consoleErrors.push("resource " + r.status() + ": " + r.url());
     }
   });
@@ -218,6 +224,7 @@ async function summaryLabelExists(page, label, name) {
     await capitalScenario(page);
     await dividendScenario(page);
     await returnsScenario(page);
+    await navDatesScenario(page);
     await plansScenario(page);
     await rebalanceScenario(page);
   } finally {
@@ -501,6 +508,60 @@ async function returnsScenario(page) {
   await page.screenshot({ path: SHOTS + "/16-returns-curve.png" });
 }
 
+async function navDatesScenario(page) {
+  // R1: 真实 AKShare 净值日期下拉（可用时显示真实日期，不可用时显示提示）。
+  await page.waitForSelector(".returns-panel .returns-date-picker", { timeout: 10000 });
+
+  const token = process.env.QA_TOKEN || "qa-token";
+
+  for (let i = 0; i < 200 && lastNavDatesResponse === null; i++) {
+    await page.waitForTimeout(100);
+  }
+
+  const navDates = lastNavDatesResponse || {};
+  const dates = Array.isArray(navDates.dates) ? navDates.dates : [];
+  const pickerState = await page.getAttribute(".returns-date-picker", "data-nav-dates-state");
+  const optionValues = await page
+    .locator(".returns-date-input option")
+    .evaluateAll((elements) => elements.map((element) => element.value));
+  const emptyExists = (await page.locator(".returns-date-empty").count()) === 1;
+  const emptyText = ((await page.textContent(".returns-date-empty")) || "").trim();
+
+  check(
+    "R1a 真实可用时下拉显示真实净值日期",
+    navDates.code === "000001" &&
+      dates.includes("2026-09-21") &&
+      pickerState === "available" &&
+      optionValues.includes("2026-09-21") &&
+      emptyExists &&
+      emptyText === "暂无真实净值数据",
+    `state=${pickerState} dates=${JSON.stringify(dates).slice(0, 160)} options=${JSON.stringify(optionValues).slice(0, 160)}`
+  );
+
+  const failure = await page.evaluate(async (token) => {
+    const response = await fetch("/api/market/nav-dates?code=999999", {
+      headers: { Authorization: `Bearer ${token}` },
+    });
+    let body = null;
+    try {
+      body = await response.json();
+    } catch {}
+    return { status: response.status, body };
+  }, token);
+
+  check(
+    "R1b 不可用时返回 503 且保留提示路径",
+    failure.status === 503 &&
+      failure.body &&
+      failure.body.error === "MARKET_DATA_UNAVAILABLE" &&
+      emptyExists &&
+      emptyText === "暂无真实净值数据",
+    `status=${failure.status} body=${JSON.stringify(failure.body).slice(0, 160)}`
+  );
+
+  await page.screenshot({ path: SHOTS + "/19-nav-dates.png" });
+}
+
 async function postInvestmentPlanViaApi(page, fundId, token) {
   return page.evaluate(
     async ({ fundId, token }) => {
diff --git a/qa/stub/fund-lab-python b/qa/stub/fund-lab-python
index 9cdfa6a..cefcecd 100755
--- a/qa/stub/fund-lab-python
+++ b/qa/stub/fund-lab-python
@@ -23,6 +23,12 @@ case "$OP" in
     printf '{"schema_version":"fund-lab.akshare.v1","operation":"search","source":"stub-synthetic","source_revision":"stub-1","_synthetic":true,"collected_at":"%s","instruments":[{"code":"000001","name":"桩测试基金一号","fund_type":"混合型"},{"code":"110011","name":"桩测试基金二号","fund_type":null}]}\n' "$TS"
     ;;
   nav)
+    # Sentinel code used by QA to exercise the AKShare-unavailable branch of
+    # GET /api/market/nav-dates (collector exits non-zero -> API answers 503).
+    if [ "$CODE" = "999999" ]; then
+      echo "AKShare collector failed: simulated outage for $CODE" >&2
+      exit 2
+    fi
     printf '{"schema_version":"fund-lab.akshare.v1","operation":"nav","source":"stub-synthetic","source_revision":"stub-1","_synthetic":true,"collected_at":"%s","instrument":{"code":"%s"},"observations":[{"nav_date":"2026-09-15","published_at":null,"nav":"1.1000","accumulated_nav":null,"daily_return":null},{"nav_date":"2026-09-16","published_at":null,"nav":"1.1205","accumulated_nav":null,"daily_return":"1.86"},{"nav_date":"2026-09-17","published_at":null,"nav":"1.1180","accumulated_nav":null,"daily_return":"-0.22"},{"nav_date":"2026-09-18","published_at":null,"nav":"1.1500","accumulated_nav":null,"daily_return":"2.86"},{"nav_date":"2026-09-21","published_at":null,"nav":"1.1902","accumulated_nav":null,"daily_return":"3.49"}]}\n' "$TS" "$CODE"
     ;;
   *)
diff --git a/scripts/probe_akshare_nav_dates.py b/scripts/probe_akshare_nav_dates.py
new file mode 100644
index 0000000..255cf91
--- /dev/null
+++ b/scripts/probe_akshare_nav_dates.py
@@ -0,0 +1,81 @@
+#!/usr/bin/env python3
+"""Runtime probe for real AKShare NAV dates.
+
+This is the "can the host actually reach AKShare?" check that backs the
+`GET /api/market/nav-dates` endpoint. It talks to AKShare directly (no mocks),
+memoises the akshare frame lookup with functools.lru_cache, and prints a single
+JSON object on success:
+
+    {"code": "000001", "dates": ["2026-09-21", "2026-09-18", ...]}
+
+On any failure (missing dependency, network error, unusable payload) it writes a
+clear message to stderr and exits non-zero so callers can treat it as a skipped /
+unavailable probe instead of inventing data.
+"""
+
+import argparse
+import functools
+import json
+import sys
+
+import akshare as ak
+
+
[email protected]_cache(maxsize=8)
+def fetch_nav_frame(code: str):
+    """Fetch the since-inception unit-NAV frame for a fund (cached per code)."""
+    return ak.fund_open_fund_info_em(
+        symbol=code,
+        indicator="单位净值走势",
+        period="成立来",
+    )
+
+
+def recent_nav_dates(code: str, limit: int = 5):
+    """Return the most recent distinct NAV dates (descending) for a fund code."""
+    if len(code) != 6 or not code.isdigit():
+        raise ValueError("fund code must contain exactly six digits")
+
+    frame = fetch_nav_frame(code)
+    if frame is None or frame.empty:
+        raise RuntimeError(f"AKShare returned no NAV observations for {code}")
+
+    column = "净值日期"
+    if column not in frame.columns:
+        raise RuntimeError(f"AKShare payload for {code} is missing the {column} column")
+
+    dates = []
+    for value in frame[column].tolist():
+        text = str(value).strip()[:10]
+        if len(text) == 10 and text not in dates:
+            dates.append(text)
+
+    dates.sort(reverse=True)
+    return dates[:limit]
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Probe real AKShare NAV dates for a fund code",
+    )
+    parser.add_argument("--code", default="000001")
+    parser.add_argument("--limit", type=int, default=5)
+    args = parser.parse_args()
+
+    try:
+        dates = recent_nav_dates(args.code, args.limit)
+    except Exception as error:  # noqa: BLE001 - probe reports the concrete reason
+        print(f"AKShare NAV-date probe failed for {args.code}: {error}", file=sys.stderr)
+        return 2
+
+    if not dates:
+        print(f"AKShare NAV-date probe found no dates for {args.code}", file=sys.stderr)
+        return 2
+
+    json.dump({"code": args.code, "dates": dates}, sys.stdout, ensure_ascii=False)
+    sys.stdout.write("\n")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
diff --git a/src/FundLab.Api/App.fs b/src/FundLab.Api/App.fs
index 34b4f2d..370f503 100644
--- a/src/FundLab.Api/App.fs
+++ b/src/FundLab.Api/App.fs
@@ -331,6 +331,12 @@ type MarketDataNavApiResponse =
         observations: MarketDataObservationApiResponse list
     }
 
+type MarketNavDatesApiResponse =
+    {
+        code: string
+        dates: string list
+    }
+
 module App =
     let addOptionFriendlyJson (services: IServiceCollection) =
         let settings =
@@ -1634,7 +1640,23 @@ module App =
             GET >=> routef "/instruments/%s/nav" (getNav marketData)
         ]
 
-    let private createApplicationInternal (repository: FundRepository) (marketData: IMarketDataService option) : HttpHandler =
+    let private getMarketNavDates (probe: INavDateProbe) : HttpHandler =
+        fun next ctx ->
+            let code = ctx.Request.Query["code"].ToString()
+
+            match probe.RecentNavDates(code, 5, ctx.RequestAborted) with
+            | Ok dates ->
+                json ({ code = code.Trim(); dates = dates |> List.map dateText } : MarketNavDatesApiResponse) next ctx
+            | Error failure -> marketDataError failure next ctx
+
+    let private navDateProbeRoutes (probe: INavDateProbe) =
+        [ GET >=> route "/market/nav-dates" >=> getMarketNavDates probe ]
+
+    let private createApplicationInternal
+        (repository: FundRepository)
+        (marketData: IMarketDataService option)
+        (navDateProbe: INavDateProbe option)
+        : HttpHandler =
         let apiRoutes =
             [
                 GET >=> route "/portfolio/summary" >=> emptyPortfolio
@@ -1665,6 +1687,7 @@ module App =
                 GET >=> routef "/funds/%s" (getFund repository)
             ]
             @ (marketData |> Option.map marketDataRoutes |> Option.defaultValue [])
+            @ (navDateProbe |> Option.map navDateProbeRoutes |> Option.defaultValue [])
 
         choose [
             GET >=> route "/health" >=> health
@@ -1676,7 +1699,17 @@ module App =
         ]
 
     let createApplicationWithMarketData (repository: FundRepository) (marketData: IMarketDataService) : HttpHandler =
-        createApplicationInternal repository (Some marketData)
+        createApplicationInternal repository (Some marketData) None
+
+    let createApplicationWithNavDateProbe (repository: FundRepository) (probe: INavDateProbe) : HttpHandler =
+        createApplicationInternal repository None (Some probe)
+
+    let createApplicationWithMarketDataAndProbe
+        (repository: FundRepository)
+        (marketData: IMarketDataService)
+        (probe: INavDateProbe)
+        : HttpHandler =
+        createApplicationInternal repository (Some marketData) (Some probe)
 
     let createApplication (repository: FundRepository) : HttpHandler =
-        createApplicationInternal repository None
+        createApplicationInternal repository None None
diff --git a/src/FundLab.Api/FundLab.Api.fsproj b/src/FundLab.Api/FundLab.Api.fsproj
index 04724c0..ed2c637 100644
--- a/src/FundLab.Api/FundLab.Api.fsproj
+++ b/src/FundLab.Api/FundLab.Api.fsproj
@@ -17,8 +17,9 @@
     <Compile Include="Health.fs" />
     <Compile Include="MarketData.fs" />
     <Compile Include="Persistence.fs" />
-    <Compile Include="MarketDataService.fs" />
-    <Compile Include="App.fs" />
+        <Compile Include="MarketDataService.fs" />
+        <Compile Include="NavDateProbe.fs" />
+        <Compile Include="App.fs" />
     <Compile Include="Program.fs" />
   </ItemGroup>
   <ItemGroup>
diff --git a/src/FundLab.Api/NavDateProbe.fs b/src/FundLab.Api/NavDateProbe.fs
new file mode 100644
index 0000000..0437fd8
--- /dev/null
+++ b/src/FundLab.Api/NavDateProbe.fs
@@ -0,0 +1,57 @@
+namespace FundLab.Api
+
+open System
+open System.Collections.Concurrent
+open System.Threading
+
+/// Read-only probe that returns the most recent NAV dates for a fund code.
+///
+/// This is the "real data first" seam for the market NAV-date endpoint: the only
+/// implementation talks to the AKShare collector, and there is deliberately no
+/// synthetic fallback. A failed probe surfaces as a MarketDataFailure so the API
+/// can answer 503 with the underlying reason instead of inventing dates.
+type INavDateProbe =
+    abstract RecentNavDates: code: string * limit: int * CancellationToken -> Result<DateOnly list, MarketDataFailure>
+
+/// AKShare-backed probe. Successful lookups are memoised per fund code
+/// (the F# equivalent of functools.lru_cache) so repeated UI reads during one
+/// process do not re-spawn the collector; failures are never cached.
+type AkshareNavDateProbe(collector: IMarketDataCollector) =
+    let cache = ConcurrentDictionary<string, DateOnly list>(StringComparer.Ordinal)
+
+    let isFundCode (value: string) =
+        not (String.IsNullOrWhiteSpace value)
+        && value.Length = 6
+        && value |> Seq.forall Char.IsDigit
+
+    let clip limit =
+        if limit < 1 then 1
+        elif limit > 60 then 60
+        else limit
+
+    member _.Clear() = cache.Clear()
+
+    interface INavDateProbe with
+        member _.RecentNavDates(code, limit, token) =
+            let normalized = if isNull code then "" else code.Trim()
+
+            if not (isFundCode normalized) then
+                Error(InvalidMarketDataRequest "fund code must contain exactly six digits")
+            else
+                match cache.TryGetValue normalized with
+                | true, cached -> Ok(cached |> List.truncate (clip limit))
+                | _ ->
+                    match collector.FetchNav(normalized, token) with
+                    | Error message -> Error(MarketDataCollectorUnavailable message)
+                    | Ok json ->
+                        match MarketData.parseNavPayload json with
+                        | Error message -> Error(InvalidMarketDataPayload message)
+                        | Ok payload ->
+                            let dates =
+                                payload.Observations
+                                |> List.map (fun observation -> observation.NavDate)
+                                |> List.distinct
+                                |> List.sortDescending
+
+                            cache.[normalized] <- dates
+                            Ok(dates |> List.truncate (clip limit))
diff --git a/src/FundLab.Api/Persistence.fs b/src/FundLab.Api/Persistence.fs
index 7a7ab32..6028b7c 100644
--- a/src/FundLab.Api/Persistence.fs
+++ b/src/FundLab.Api/Persistence.fs
@@ -59,6 +59,18 @@ module ConfirmationPolicy =
             let candidate = if local.TimeOfDay >= cutoffTimeOfDay then date.AddDays 1 else date
             rollToWeekday candidate
 
+    /// Calendar date used to bucket events (cash flows, holdings) on the returns
+    /// timeline. Shares the FUND_LAB_TEST_TRADE_DATE anchor with tradeDateFor so a
+    /// pinned suite does not drift when the host crosses midnight; production (no
+    /// pin) is exactly the Shanghai calendar date of the moment.
+    let eventDateFor (moment: DateTimeOffset) : DateOnly =
+        match Environment.GetEnvironmentVariable("FUND_LAB_TEST_TRADE_DATE") with
+        | value when not (String.IsNullOrWhiteSpace value) ->
+            match DateOnly.TryParseExact(value, "yyyy-MM-dd", CultureInfo.InvariantCulture, DateTimeStyles.None) with
+            | true, anchored -> anchored
+            | _ -> shanghaiDate moment
+        | _ -> shanghaiDate moment
+
     type NavQuote =
         { NavDate: DateOnly
           Nav: decimal
@@ -4867,7 +4879,7 @@ type FundRepository(connectionString: string) =
         match this.GetFund fundId with
         | None -> None
         | Some fund ->
-            let today = ConfirmationPolicy.shanghaiDate DateTimeOffset.UtcNow
+            let today = ConfirmationPolicy.eventDateFor DateTimeOffset.UtcNow
             let deposits = this.GetCapitalDeposits fundId
             let orders = this.GetSubscriptionOrders fundId
             let redemptions = this.GetRedemptionOrders fundId
@@ -4902,7 +4914,7 @@ type FundRepository(connectionString: string) =
                         |> List.map (fun observation -> observation.NavDate))
                 |> Set.ofList
 
-            let creationDate = ConfirmationPolicy.shanghaiDate fund.CreatedAt
+            let creationDate = ConfirmationPolicy.eventDateFor fund.CreatedAt
 
             let dividendCredited =
                 dividends
@@ -4926,7 +4938,7 @@ type FundRepository(connectionString: string) =
             else
                 let eventDates =
                     [ yield creationDate
-                      yield! deposits |> List.map (fun deposit -> ConfirmationPolicy.shanghaiDate deposit.CreatedAt)
+                      yield! deposits |> List.map (fun deposit -> ConfirmationPolicy.eventDateFor deposit.CreatedAt)
                       yield! orders |> List.map (fun order -> order.TradeDate)
                       yield! redemptions |> List.map (fun order -> order.TradeDate)
                       yield! dividendCredited |> List.map (fun record -> record.NavDate) ]
@@ -4964,7 +4976,7 @@ type FundRepository(connectionString: string) =
 
                 for date in dates do
                     for deposit in deposits do
-                        if ConfirmationPolicy.shanghaiDate deposit.CreatedAt = date then
+                        if ConfirmationPolicy.eventDateFor deposit.CreatedAt = date then
                             availableCash <- availableCash + deposit.Amount
                             cumulativeDeposits <- cumulativeDeposits + deposit.Amount
 
diff --git a/src/FundLab.Api/Program.fs b/src/FundLab.Api/Program.fs
index b7d0ef6..ba5936e 100644
--- a/src/FundLab.Api/Program.fs
+++ b/src/FundLab.Api/Program.fs
@@ -19,8 +19,9 @@ let main argv =
     repository.EnsureSchema()
     let collector = ProcessMarketDataCollector.FromEnvironment() :> IMarketDataCollector
     let marketData = MarketDataService(repository, collector) :> IMarketDataService
+    let navDateProbe = AkshareNavDateProbe(collector) :> INavDateProbe
 
     let app = builder.Build()
-    app.UseGiraffe(App.createApplicationWithMarketData repository marketData)
+    app.UseGiraffe(App.createApplicationWithMarketDataAndProbe repository marketData navDateProbe)
     app.Run()
     0
diff --git a/src/FundLab.Web/App.fs b/src/FundLab.Web/App.fs
index 8eb598e..44130de 100644
--- a/src/FundLab.Web/App.fs
+++ b/src/FundLab.Web/App.fs
@@ -373,6 +373,12 @@ type RawReturns =
         points: RawReturnsPoint array
     }
 
+type RawMarketNavDates =
+    {
+        code: string
+        dates: string array
+    }
+
 type CreateAttempt =
     {
         idempotencyKey: string
@@ -709,6 +715,9 @@ module Api =
     [<Import("getReturns", "./src/api.js")>]
     let getReturns (token: string) (fundId: string) : JS.Promise<RawReturns> = jsNative
 
+    [<Import("getMarketNavDates", "./src/api.js")>]
+    let getMarketNavDates (token: string) (code: string) : JS.Promise<RawMarketNavDates> = jsNative
+
     [<Import("createCapitalDeposit", "./src/api.js")>]
     let createCapitalDeposit (token: string) (fundId: string) (payload: CreateCapitalPayload) : JS.Promise<obj> = jsNative
 
@@ -1049,6 +1058,11 @@ type Model =
         returnsReadSeq: int
         returnsInFlight: bool
         returns: FundReturns option
+        navDatesReadSeq: int
+        navDatesInFlight: bool
+        navDates: string list
+        navDatesAvailable: bool
+        returnsSelectedDate: string option
         planReadSeq: int
         planInFlight: bool
         planRunSeq: int
@@ -1142,6 +1156,10 @@ type Msg =
     | ReturnsReadRequested
     | ReturnsReadCompleted of requestId: int * returns: RawReturns
     | ReturnsReadFailed of requestId: int * message: string
+    | NavDatesReadRequested
+    | NavDatesReadCompleted of requestId: int * dates: RawMarketNavDates
+    | NavDatesReadFailed of requestId: int * message: string
+    | ReturnsDateChanged of string
     | InvestmentPlansReadRequested
     | InvestmentPlansReadCompleted of requestId: int * plans: RawInvestmentPlan array
     | InvestmentPlansReadFailed of requestId: int * message: string
@@ -1252,6 +1270,11 @@ let init () =
         returnsReadSeq = 0
         returnsInFlight = false
         returns = None
+        navDatesReadSeq = 0
+        navDatesInFlight = false
+        navDates = []
+        navDatesAvailable = false
+        returnsSelectedDate = None
         planReadSeq = 0
         planInFlight = false
         planRunSeq = 0
@@ -1421,6 +1444,13 @@ let private readReturnsCommand token fundId requestId =
         (fun returns -> ReturnsReadCompleted(requestId, returns))
         (fun error -> ReturnsReadFailed(requestId, errorText error))
 
+let private readNavDatesCommand token code requestId =
+    Cmd.OfPromise.either
+        (fun () -> Api.getMarketNavDates token code)
+        ()
+        (fun dates -> NavDatesReadCompleted(requestId, dates))
+        (fun error -> NavDatesReadFailed(requestId, errorText error))
+
 let private readInvestmentPlansCommand token fundId requestId =
     Cmd.OfPromise.either
         (fun () -> Api.getInvestmentPlans token fundId)
@@ -1512,6 +1542,11 @@ let update message model =
                 returnsReadSeq = model.returnsReadSeq + 1
                 returnsInFlight = false
                 returns = None
+                navDatesReadSeq = model.navDatesReadSeq + 1
+                navDatesInFlight = false
+                navDates = []
+                navDatesAvailable = false
+                returnsSelectedDate = None
                 planReadSeq = model.planReadSeq + 1
                 planInFlight = false
                 planRunSeq = model.planRunSeq + 1
@@ -1721,6 +1756,11 @@ let update message model =
                     returnsReadSeq = model.returnsReadSeq + 1
                     returnsInFlight = false
                     returns = None
+                    navDatesReadSeq = model.navDatesReadSeq + 1
+                    navDatesInFlight = false
+                    navDates = []
+                    navDatesAvailable = false
+                    returnsSelectedDate = None
                     planReadSeq = model.planReadSeq + 1
                     planInFlight = false
                     planRunSeq = model.planRunSeq + 1
@@ -2499,7 +2539,7 @@ let update message model =
                     returnsInFlight = true
                     error = None
             },
-            readReturnsCommand model.token fund.id requestId
+            Cmd.batch [ readReturnsCommand model.token fund.id requestId; Cmd.ofMsg NavDatesReadRequested ]
         | Some _ -> { model with error = Some "请输入 API token" }, Cmd.none
         | None -> model, Cmd.none
     | ReturnsReadCompleted (requestId, returns) ->
@@ -2518,6 +2558,61 @@ let update message model =
             { model with returnsInFlight = false; error = Some message }, Cmd.none
         else
             model, Cmd.none
+    | NavDatesReadRequested ->
+        match model.createdFund with
+        | Some _ when String.IsNullOrWhiteSpace model.token ->
+            { model with error = Some "请输入 API token" }, Cmd.none
+        | Some _ ->
+            let heldCode =
+                model.positions
+                |> Option.bind (fun positions -> positions.positions |> List.tryHead)
+                |> Option.map (fun position -> position.instrumentCode)
+
+            match heldCode with
+            | Some code ->
+                let requestId = model.navDatesReadSeq + 1
+
+                {
+                    model with
+                        navDatesReadSeq = requestId
+                        navDatesInFlight = true
+                },
+                readNavDatesCommand model.token code requestId
+            | None ->
+                {
+                    model with
+                        navDates = []
+                        navDatesAvailable = false
+                        navDatesInFlight = false
+                },
+                Cmd.none
+        | None -> model, Cmd.none
+    | NavDatesReadCompleted (requestId, dates) ->
+        if requestId = model.navDatesReadSeq then
+            let resolved = dates.dates |> Array.toList
+
+            {
+                model with
+                    navDates = resolved
+                    navDatesAvailable = not (List.isEmpty resolved)
+                    navDatesInFlight = false
+            },
+            Cmd.none
+        else
+            model, Cmd.none
+    | NavDatesReadFailed (requestId, _) ->
+        if requestId = model.navDatesReadSeq then
+            {
+                model with
+                    navDates = []
+                    navDatesAvailable = false
+                    navDatesInFlight = false
+            },
+            Cmd.none
+        else
+            model, Cmd.none
+    | ReturnsDateChanged value ->
+        { model with returnsSelectedDate = (if String.IsNullOrWhiteSpace value then None else Some value) }, Cmd.none
     | InvestmentPlansReadRequested ->
         match model.createdFund with
         | Some fund when not (String.IsNullOrWhiteSpace model.token) ->
@@ -3889,9 +3984,15 @@ let private returnsChartView (points: ReturnsPoint list) =
         ]
 
 let private returnsPanel model dispatch =
-    let latest (selector: ReturnsPoint -> string option) =
-        model.returns
-        |> Option.bind (fun returns -> returns.points |> List.rev |> List.tryPick selector)
+    let visiblePoints =
+        match model.returns with
+        | None -> []
+        | Some returns ->
+            match model.returnsSelectedDate with
+            | Some selected -> returns.points |> List.filter (fun point -> point.date <= selected)
+            | None -> returns.points
+
+    let latest (selector: ReturnsPoint -> string option) = visiblePoints |> List.rev |> List.tryPick selector
 
     let totalAssets = latest (fun point -> point.totalAssets)
     let cumulativeReturn = latest (fun point -> point.cumulativeReturn)
@@ -3910,6 +4011,38 @@ let private returnsPanel model dispatch =
                     Html.span [ prop.className "section-note"; prop.text "Returns - cash-flow adjusted" ]
                 ]
             ]
+            Html.div [
+                prop.className "returns-date-picker"
+                prop.custom (
+                    "data-nav-dates-state",
+                    (if model.navDatesAvailable then "available" else "empty")
+                )
+                prop.children [
+                    Html.label [
+                        prop.className "field-label"
+                        prop.children [
+                            Html.span "真实净值日期"
+                            Html.select [
+                                prop.className "text-input returns-date-input"
+                                prop.disabled (not model.navDatesAvailable)
+                                prop.value (defaultArg model.returnsSelectedDate "")
+                                prop.onChange (fun value -> dispatch (ReturnsDateChanged value))
+                                prop.children [
+                                    Html.option [ prop.value ""; prop.text "最新" ]
+                                    yield!
+                                        (model.navDates
+                                         |> List.map (fun date -> Html.option [ prop.value date; prop.text date ]))
+                                ]
+                            ]
+                        ]
+                    ]
+                    Html.p [
+                        prop.className "returns-date-empty"
+                        prop.hidden model.navDatesAvailable
+                        prop.text "暂无真实净值数据"
+                    ]
+                ]
+            ]
             match model.returns with
             | None ->
                 Html.p [ prop.className "hint"; prop.text "创建基金后可读取收益曲线。" ]
@@ -3945,7 +4078,7 @@ let private returnsPanel model dispatch =
                                 ]
                             ]
                         ]
-                        returnsChartView returns.points
+                        returnsChartView visiblePoints
                         Html.p [
                             prop.className "returns-note"
                             prop.text "蓝线 总资产 / 橙线 单位净值（各自归一化）；缺少净值的数据点不连线，也不补零。"
diff --git a/src/FundLab.Web/src/api.js b/src/FundLab.Web/src/api.js
index 79b20b0..80ded41 100644
--- a/src/FundLab.Web/src/api.js
+++ b/src/FundLab.Web/src/api.js
@@ -127,6 +127,10 @@ export function getReturns(token, fundId) {
   return requestJson(`/api/funds/${encodeURIComponent(fundId)}/returns`, token);
 }
 
+export function getMarketNavDates(token, code) {
+  return requestJson(`/api/market/nav-dates?code=${encodeURIComponent(code)}`, token);
+}
+
 export function createSipPlan(token, fundId, payload) {
   const body = `{"instrumentCode":${JSON.stringify(payload.instrumentCode)},"amount":${JSON.stringify(payload.amount)},"frequency":${JSON.stringify(payload.frequency)}}`;
   return requestJson(`/api/funds/${encodeURIComponent(fundId)}/sip/plans`, token, {
diff --git a/src/FundLab.Web/src/styles.css b/src/FundLab.Web/src/styles.css
index a3bdfba..4cdf165 100644
--- a/src/FundLab.Web/src/styles.css
+++ b/src/FundLab.Web/src/styles.css
@@ -545,6 +545,27 @@ h2 {
   font-size: 11px;
 }
 
+.returns-date-picker {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: flex-end;
+  gap: 12px;
+  margin-bottom: 10px;
+}
+
+.returns-date-picker .field-label {
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+  font-size: 12px;
+  color: #475569;
+}
+
+.returns-date-empty {
+  color: #b45309;
+  font-size: 12px;
+}
+
 .returns-pending {
   color: #b45309;
   font-size: 12px;
diff --git a/tests/FundLab.Api.Tests/FundLab.Api.Tests.fsproj b/tests/FundLab.Api.Tests/FundLab.Api.Tests.fsproj
index 374c63e..a77e503 100644
--- a/tests/FundLab.Api.Tests/FundLab.Api.Tests.fsproj
+++ b/tests/FundLab.Api.Tests/FundLab.Api.Tests.fsproj
@@ -29,6 +29,7 @@
         <Compile Include="ReturnsTests.fs" />
         <Compile Include="InvestmentPlanTests.fs" />
         <Compile Include="RebalanceTests.fs" />
+        <Compile Include="NavDateProbeTests.fs" />
     <Compile Include="Program.fs" />
   </ItemGroup>
 </Project>
diff --git a/tests/FundLab.Api.Tests/NavDateProbeTests.fs b/tests/FundLab.Api.Tests/NavDateProbeTests.fs
new file mode 100644
index 0000000..0f7e506
--- /dev/null
+++ b/tests/FundLab.Api.Tests/NavDateProbeTests.fs
@@ -0,0 +1,248 @@
+namespace FundLab.Api.Tests
+
+open System
+open System.Diagnostics
+open System.IO
+open System.Text.Json
+open System.Threading
+open Xunit
+open FundLab.Api
+
+module NavDateProbeSupport =
+    let navPayloadJson (code: string) (observations: (string * string) list) =
+        let body =
+            observations
+            |> List.map (fun (date, nav) ->
+                sprintf
+                    "{\"nav_date\":\"%s\",\"published_at\":null,\"nav\":\"%s\",\"accumulated_nav\":null,\"daily_return\":null}"
+                    date
+                    nav)
+            |> String.concat ","
+
+        sprintf
+            "{\"schema_version\":\"fund-lab.akshare.v1\",\"operation\":\"nav\",\"source\":\"akshare\",\"source_revision\":\"akshare-test/eastmoney\",\"collected_at\":\"2026-09-21T08:00:00Z\",\"instrument\":{\"code\":\"%s\"},\"observations\":[%s]}"
+            code
+            body
+
+    let collectorReturning (fetch: unit -> Result<string, string>) =
+        { new IMarketDataCollector with
+            member _.Search(_, _) = Ok ""
+            member _.FetchNav(_, _) = fetch () }
+
+    let realAksharePython () =
+        let configured = Environment.GetEnvironmentVariable("FUND_LAB_AKSHARE_PYTHON")
+
+        if String.IsNullOrWhiteSpace configured then
+            None
+        elif File.Exists configured then
+            Some configured
+        else
+            let path = Environment.GetEnvironmentVariable("PATH") |> Option.ofObj |> Option.defaultValue ""
+
+            path.Split(Path.PathSeparator, StringSplitOptions.RemoveEmptyEntries)
+            |> Array.tryPick (fun directory ->
+                let candidate = Path.Combine(directory, configured)
+                if File.Exists candidate then Some candidate else None)
+
+    let repositoryRoot () =
+        let mutable directory = DirectoryInfo(AppContext.BaseDirectory)
+
+        while not (isNull directory)
+              && not (File.Exists(Path.Combine(directory.FullName, "scripts", "probe_akshare_nav_dates.py"))) do
+            directory <- directory.Parent
+
+        if isNull directory then
+            failwith "could not locate scripts/probe_akshare_nav_dates.py from the test output directory"
+        else
+            directory.FullName
+
+/// xUnit has no first-class runtime skip in 2.x, so this fact sets Skip during
+/// discovery when the host has no reachable AKShare interpreter configured.
+/// That keeps the live probe detectable ("skipped, not faked") instead of red.
+type RealAkshareFactAttribute() =
+    inherit FactAttribute()
+
+    do
+        if (NavDateProbeSupport.realAksharePython ()).IsNone then
+            base.Skip <-
+                "set FUND_LAB_AKSHARE_PYTHON to a python interpreter with akshare installed to run the live probe"
+
+[<Collection("postgres")>]
+type NavDateProbeTests(fixture: PostgresFixture) =
+    let repository () = FundRepository(fixture.ConnectionString)
+
+    let appWithProbe (probe: INavDateProbe) =
+        App.createApplicationWithNavDateProbe (repository ()) probe
+
+    [<Fact>]
+    member _.``probe parses, dedupes, sorts descending and truncates``() =
+        let payload =
+            NavDateProbeSupport.navPayloadJson
+                "000001"
+                [
+                    "2026-09-16", "1.1205"
+                    "2026-09-21", "1.1902"
+                    "2026-09-16", "1.1205"
+                    "2026-09-18", "1.1500"
+                    "2026-09-17", "1.1180"
+                    "2026-09-15", "1.1000"
+                    "2026-09-11", "1.0900"
+                ]
+
+        let probe = AkshareNavDateProbe(NavDateProbeSupport.collectorReturning (fun () -> Ok payload)) :> INavDateProbe
+
+        match probe.RecentNavDates("000001", 5, CancellationToken.None) with
+        | Ok dates ->
+            Assert.Equal<DateOnly list>(
+                [
+                    DateOnly(2026, 9, 21)
+                    DateOnly(2026, 9, 18)
+                    DateOnly(2026, 9, 17)
+                    DateOnly(2026, 9, 16)
+                    DateOnly(2026, 9, 15)
+                ],
+                dates
+            )
+        | Error failure -> failwithf "expected NAV dates, got %A" failure
+
+    [<Fact>]
+    member _.``probe memoises successful lookups per code``() =
+        let mutable calls = 0
+
+        let collector =
+            NavDateProbeSupport.collectorReturning (fun () ->
+                calls <- calls + 1
+                Ok(NavDateProbeSupport.navPayloadJson "000001" [ "2026-09-21", "1.1902" ]))
+
+        let probe = AkshareNavDateProbe(collector) :> INavDateProbe
+        let first = probe.RecentNavDates("000001", 5, CancellationToken.None)
+        let second = probe.RecentNavDates("000001", 5, CancellationToken.None)
+
+        Assert.Equal(Ok [ DateOnly(2026, 9, 21) ], first)
+        Assert.Equal(Ok [ DateOnly(2026, 9, 21) ], second)
+        Assert.Equal(1, calls)
+
+    [<Fact>]
+    member _.``probe rejects a malformed fund code without touching the collector``() =
+        let collector =
+            NavDateProbeSupport.collectorReturning (fun () -> failwith "collector should not be called")
+
+        let probe = AkshareNavDateProbe(collector) :> INavDateProbe
+
+        match probe.RecentNavDates("abc", 5, CancellationToken.None) with
+        | Error (InvalidMarketDataRequest message) -> Assert.Contains("six digits", message)
+        | other -> failwithf "expected InvalidMarketDataRequest, got %A" other
+
+    [<Fact>]
+    member _.``probe maps collector failures to an unavailable reason``() =
+        let collector =
+            NavDateProbeSupport.collectorReturning (fun () -> Error "AKShare is unreachable: connection timed out")
+
+        let probe = AkshareNavDateProbe(collector) :> INavDateProbe
+
+        match probe.RecentNavDates("000001", 5, CancellationToken.None) with
+        | Error (MarketDataCollectorUnavailable message) -> Assert.Contains("connection timed out", message)
+        | other -> failwithf "expected MarketDataCollectorUnavailable, got %A" other
+
+    [<Fact>]
+    member _.``probe maps malformed payloads to an invalid payload reason``() =
+        let probe =
+            AkshareNavDateProbe(NavDateProbeSupport.collectorReturning (fun () -> Ok "{not-json")) :> INavDateProbe
+
+        match probe.RecentNavDates("000001", 5, CancellationToken.None) with
+        | Error (InvalidMarketDataPayload _) -> ()
+        | other -> failwithf "expected InvalidMarketDataPayload, got %A" other
+
+    [<Fact>]
+    member _.``market nav-dates endpoint returns the probe dates``() =
+        let probe =
+            { new INavDateProbe with
+                member _.RecentNavDates(code, limit, _) =
+                    Assert.Equal("000001", code)
+                    Assert.Equal(5, limit)
+                    Ok [ DateOnly(2026, 9, 21); DateOnly(2026, 9, 18) ] }
+
+        let status, body =
+            PersistenceTestHelpers.invoke
+                (appWithProbe probe)
+                "GET"
+                "/api/market/nav-dates?code=000001"
+                [ "Authorization", "Bearer test-token" ]
+                ""
+
+        Assert.Equal(200, status)
+        Assert.Contains("\"code\":\"000001\"", body)
+        Assert.Contains("\"dates\":[\"2026-09-21\",\"2026-09-18\"]", body)
+
+    [<Fact>]
+    member _.``market nav-dates endpoint answers 503 when the probe fails``() =
+        let probe =
+            { new INavDateProbe with
+                member _.RecentNavDates(_, _, _) =
+                    Error(MarketDataCollectorUnavailable "AKShare is unreachable: connection timed out") }
+
+        let status, body =
+            PersistenceTestHelpers.invoke
+                (appWithProbe probe)
+                "GET"
+                "/api/market/nav-dates?code=000001"
+                [ "Authorization", "Bearer test-token" ]
+                ""
+
+        Assert.Equal(503, status)
+        Assert.Contains("MARKET_DATA_UNAVAILABLE", body)
+        Assert.Contains("connection timed out", body)
+
+    [<Fact>]
+    member _.``market nav-dates endpoint rejects a malformed code with 400``() =
+        let probe =
+            { new INavDateProbe with
+                member _.RecentNavDates(_, _, _) =
+                    Error(InvalidMarketDataRequest "fund code must contain exactly six digits") }
+
+        let status, body =
+            PersistenceTestHelpers.invoke
+                (appWithProbe probe)
+                "GET"
+                "/api/market/nav-dates?code=abc"
+                [ "Authorization", "Bearer test-token" ]
+                ""
+
+        Assert.Equal(400, status)
+        Assert.Contains("INVALID_MARKET_DATA_REQUEST", body)
+
+    [<RealAkshareFact>]
+    member _.``live AKShare probe returns the five most recent NAV dates``() =
+        let python = (NavDateProbeSupport.realAksharePython ()).Value
+        let script = Path.Combine(NavDateProbeSupport.repositoryRoot (), "scripts", "probe_akshare_nav_dates.py")
+
+        let startInfo = ProcessStartInfo(python)
+        startInfo.ArgumentList.Add script
+        startInfo.ArgumentList.Add "--code"
+        startInfo.ArgumentList.Add "000001"
+        startInfo.ArgumentList.Add "--limit"
+        startInfo.ArgumentList.Add "5"
+        startInfo.RedirectStandardOutput <- true
+        startInfo.RedirectStandardError <- true
+        startInfo.UseShellExecute <- false
+
+        match Environment.GetEnvironmentVariable("FUND_LAB_AKSHARE_PYTHONPATH") with
+        | value when not (String.IsNullOrWhiteSpace value) -> startInfo.Environment["PYTHONPATH"] <- value
+        | _ -> ()
+
+        use probeProcess = Process.Start startInfo
+        let standardOutput = probeProcess.StandardOutput.ReadToEnd()
+        let standardError = probeProcess.StandardError.ReadToEnd()
+        probeProcess.WaitForExit 60000 |> ignore
+
+        Assert.True(probeProcess.ExitCode = 0, sprintf "probe exited with %d: %s" probeProcess.ExitCode standardError)
+
+        use document = JsonDocument.Parse standardOutput
+
+        let dates =
+            document.RootElement.GetProperty("dates").EnumerateArray()
+            |> Seq.map (fun element -> element.GetString())
+            |> Seq.toList
+
+        Assert.Equal(5, List.length dates)
+        Assert.Equal<string list>(List.sortDescending dates, dates)