diff --git a/app/service/market_price_sync_service.py b/app/service/market_price_sync_service.py
index 03285fd..b6d49c4 100644
--- a/app/service/market_price_sync_service.py
+++ b/app/service/market_price_sync_service.py
@@ -48,9 +48,11 @@ from app.infrastructure.db import SessionFactory
 from app.infrastructure.fund_market_adapter import EastmoneyFundAdapter
 from app.model.fund import FundMarketPrice, FundProduct
 
-#: 来源口径。带 `+shares_estimated` 表示 `total_fund_shares` 是推算的。
+#: 来源口径。带 `+shares_estimated` 表示 `total_fund_shares` 是推算的；
+#: `eastmoney_nav_fallback` 表示腾讯行情没有这只是，改用东财净值构造（见 `_nav_fallback`）。
 SOURCE_QUOTE = "tencent_quote"
 SOURCE_QUOTE_ESTIMATED = "tencent_quote+shares_estimated"
+SOURCE_NAV_FALLBACK = "eastmoney_nav_fallback"
 
 PRICE_QUANT = Decimal("0.000001")
 AMOUNT_QUANT = Decimal("0.01")
@@ -100,6 +102,14 @@ class MarketPriceSyncService:
         codes = [str(row["product_code"]) for row in products]
         code_to_id = {str(row["product_code"]): int(row["id"]) for row in products}
         quotes = await self.adapter.fetch_tencent_quotes(codes)
+        # 行情源没有的产品，**在事务外**用净值源补上（在事务里做网络请求会拉长事务）。
+        fallbacks: dict[str, dict[str, Any]] = {}
+        for code in codes:
+            if quotes.get(code):
+                continue
+            fallback = await self._nav_fallback(code)
+            if fallback is not None:
+                fallbacks[code] = fallback
         # 只为**既没有已登记份额、行情里也没有总市值**的产品去抓季度规模兜底。
         need_scale = [
             code
@@ -116,9 +126,10 @@ class MarketPriceSyncService:
             for row in products:
                 code = str(row["product_code"])
                 product_id = int(row["id"])
-                quote = quotes.get(code)
+                quote = quotes.get(code) or fallbacks.get(code)
+                used_fallback = code in fallbacks
                 if not quote:
-                    skipped.append({"product_code": code, "reason": "行情源未返回该产品"})
+                    skipped.append({"product_code": code, "reason": "行情源与净值源都没有它"})
                     continue
                 trade_date = self._trade_date(quote, now)
                 if trade_date is None:
@@ -134,7 +145,8 @@ class MarketPriceSyncService:
                     })
                     continue
                 if await self._upsert(
-                    session, product_id, trade_date, quote, shares, estimated, now
+                    session, product_id, trade_date, quote, shares,
+                    self._source_of(used_fallback, estimated), now,
                 ):
                     written += 1
 
@@ -162,15 +174,54 @@ class MarketPriceSyncService:
 
     @staticmethod
     def _trade_date(quote: Mapping[str, Any], fallback: datetime) -> date | None:
-        """从腾讯的行情时间戳（`YYYYMMDDHHMMSS`）取交易日；解析不出就用当天。"""
+        """取交易日：优先腾讯行情时间戳（`YYYYMMDDHHMMSS`），其次净值日期，最后当天。"""
         raw = str(quote.get("quoted_at") or "")
         if len(raw) >= 8 and raw[:8].isdigit():
             try:
                 return date(int(raw[:4]), int(raw[4:6]), int(raw[6:8]))
             except ValueError:
                 return fallback.date()
+        nav_date = quote.get("nav_date")
+        if isinstance(nav_date, date):
+            return nav_date
         return fallback.date()
 
+    @staticmethod
+    def _source_of(used_fallback: bool, estimated: bool) -> str:
+        """这一行的来源口径：净值降级 > 含估算份额 > 纯行情。"""
+        if used_fallback:
+            return SOURCE_NAV_FALLBACK
+        return SOURCE_QUOTE_ESTIMATED if estimated else SOURCE_QUOTE
+
+    async def _nav_fallback(self, code: str) -> dict[str, Any] | None:
+        """行情源没有这只是时，用东财历史净值构造一条**降级**行情。
+
+        为什么可以接受：`source` 会写成 `eastmoney_nav_fallback` 明确标注来源，
+        `volume`/`turnover` 留空（净值接口不提供量额），不编造任何数字；
+        开高低用净值同值（该接口只给一个价格）。
+
+        ⚠️ **净值不等于市价**：若该产品确实在交易所交易，用它当收盘价会有折溢价偏差。
+        所以这条路径只应落在"行情源没有覆盖"的产品上，且值得业务侧复核 ——
+        实测触发它的 `160129` 是 C 类份额（其 A 类 `160128` 在腾讯源有行情），
+        它很可能未上市交易，那它本就不该出现在场内产品列表里。
+        """
+        history = await self.adapter.fetch_history(code, date.today())
+        nav = history.get("nav")
+        if nav is None or history.get("degraded"):
+            return None
+        return {
+            "code": code,
+            "open": nav,
+            "close": nav,
+            "high": nav,
+            "low": nav,
+            "volume": None,
+            "turnover": None,
+            "total_market_value_yi": None,
+            "quoted_at": None,
+            "nav_date": history.get("nav_date"),
+        }
+
     @staticmethod
     def _resolve_shares(
         existing: Decimal | None,
@@ -203,7 +254,7 @@ class MarketPriceSyncService:
         trade_date: date,
         quote: Mapping[str, Any],
         shares: Decimal,
-        estimated: bool,
+        source: str,
         now: datetime,
     ) -> bool:
         """按 `(product_id, trade_date)` 覆盖写一行；返回是否真的写了。"""
@@ -218,7 +269,7 @@ class MarketPriceSyncService:
             "volume": MarketPriceSyncService._q_optional(quote.get("volume")),
             "turnover_amount": MarketPriceSyncService._q_optional(quote.get("turnover")),
             "total_fund_shares": shares,
-            "source": SOURCE_QUOTE_ESTIMATED if estimated else SOURCE_QUOTE,
+            "source": source,
             "source_updated_at": now,
         }
         existing = await session.scalar(