diff --git a/YLErpDAL/Modules/SwapModule/ReturnLegs/MtmCalc.cs b/YLErpDAL/Modules/SwapModule/ReturnLegs/MtmCalc.cs
index 7fab2a8f..7dedab2c 100644
--- a/YLErpDAL/Modules/SwapModule/ReturnLegs/MtmCalc.cs
+++ b/YLErpDAL/Modules/SwapModule/ReturnLegs/MtmCalc.cs
@@ -23,4 +23,8 @@ public static class MtmCalc
     /// <summary>浮动端总未实现盈亏 = 盯市盈亏 + 分红 + 待结费用。原 4 处内联收口到此。</summary>
     public static decimal ReturnLegProfitSum(decimal mtmPnl, decimal dividendSum, decimal feePending)
         => mtmPnl + dividendSum + feePending;
+
+    /// <summary>加权均价混合：(昨日均价×昨日量 + 今日∑(量×均额)) / 总量。原 4 处内联收口到此。</summary>
+    public static decimal BlendPrice(decimal prevPrice, decimal prevQty, decimal sumQtyTimesPrice, decimal totalQty)
+        => (prevPrice * prevQty + sumQtyTimesPrice) / totalQty;
 }
diff --git a/YLErpDAL/Modules/SwapModule/SwapEodPositionService.cs b/YLErpDAL/Modules/SwapModule/SwapEodPositionService.cs
index ead71307..dc700be1 100644
--- a/YLErpDAL/Modules/SwapModule/SwapEodPositionService.cs
+++ b/YLErpDAL/Modules/SwapModule/SwapEodPositionService.cs
@@ -1986,16 +1986,16 @@ namespace YLErp.Modules.SwapModule
                     {
                         posiQty = 0;
                     }
-                    curretEod.PosiGrossPrice = (eod.PosiGrossPrice * eod.PosiQuantity + openFlowEvents.Sum(a => a.Quantity * a.TradingAmountAvg)) / (eod.PosiQuantity + openQty);
+                    curretEod.PosiGrossPrice = MtmCalc.BlendPrice(eod.PosiGrossPrice, eod.PosiQuantity, openFlowEvents.Sum(a => a.Quantity * a.TradingAmountAvg), eod.PosiQuantity + openQty);
                     curretEod.PosiGrossPrice = Math.Round(
                         curretEod.PosiGrossPrice,
                         GetStorageDeliveryPriceRound(curretEod.UnderlyingInstrumentType, curretEod.UnderlyingCode),
                         MidpointRounding.AwayFromZero);
-                    curretEod.PosiNetPrice = (eod.PosiNetPrice * eod.PosiQuantity + openFlowEvents.Sum(a => a.Quantity * a.TradingAmountFeeAvg)) / (eod.PosiQuantity + openQty);
+                    curretEod.PosiNetPrice = MtmCalc.BlendPrice(eod.PosiNetPrice, eod.PosiQuantity, openFlowEvents.Sum(a => a.Quantity * a.TradingAmountFeeAvg), eod.PosiQuantity + openQty);
                     curretEod.PosiNetPrice = Math.Round(curretEod.PosiNetPrice, ConsGlobal.PriceRound, MidpointRounding.AwayFromZero);
-                    curretEod.PosiNetNoFeePrice = (eod.PosiNetNoFeePrice * eod.PosiQuantity + openFlowEvents.Sum(a => a.Quantity * a.TradingAmountNetAvg)) / (eod.PosiQuantity + openQty);
+                    curretEod.PosiNetNoFeePrice = MtmCalc.BlendPrice(eod.PosiNetNoFeePrice ?? 0m, eod.PosiQuantity, openFlowEvents.Sum(a => a.Quantity * (a.TradingAmountNetAvg ?? 0m)), eod.PosiQuantity + openQty);
                     curretEod.PosiNetNoFeePrice = Math.Round(curretEod.PosiNetNoFeePrice ?? 0, ConsGlobal.PriceRound, MidpointRounding.AwayFromZero);
-                    curretEod.PosiNetFeePrice = (eod.PosiNetFeePrice * eod.PosiQuantity + openFlowEvents.Sum(a => a.Quantity * a.TradingAmountNetFeeAvg)) / (eod.PosiQuantity + openQty);
+                    curretEod.PosiNetFeePrice = MtmCalc.BlendPrice(eod.PosiNetFeePrice ?? 0m, eod.PosiQuantity, openFlowEvents.Sum(a => a.Quantity * (a.TradingAmountNetFeeAvg ?? 0m)), eod.PosiQuantity + openQty);
                     curretEod.PosiNetFeePrice = Math.Round(curretEod.PosiNetFeePrice ?? 0, ConsGlobal.PriceRound, MidpointRounding.AwayFromZero);
                 }
                 curretEod.PosiNotionalValue = curretEod.PosiGrossPrice * curretEod.PosiQuantity * curretEod.ContractSize;