diff --git a/backend/internal/handlers/stock.go b/backend/internal/handlers/stock.go
index 45d2d68..5d05d71 100644
--- a/backend/internal/handlers/stock.go
+++ b/backend/internal/handlers/stock.go
@@ -29,6 +29,7 @@ type stockRow struct {
 	Symbol    string  `json:"symbol"`
 	Name      string  `json:"name"`
 	Close     float64 `json:"close"`
+	PrevClose float64 `json:"prev_close,omitempty"`
 	ChangePct float64 `json:"change_pct"`
 	Amount    float64 `json:"amount,omitempty"`
 }
@@ -71,9 +72,9 @@ func (h *StockHandler) Overview(c *gin.Context) {
 	if err := h.DB.WithContext(ctx).Model(&models.StockDailyQuote{}).
 		Select(`
 			COUNT(*) AS total,
-			SUM(CASE WHEN change_pct > 0 THEN 1 ELSE 0 END) AS up,
-			SUM(CASE WHEN change_pct < 0 THEN 1 ELSE 0 END) AS down,
-			SUM(CASE WHEN change_pct = 0 THEN 1 ELSE 0 END) AS flat
+			SUM(CASE WHEN close > prev_close THEN 1 ELSE 0 END) AS up,
+			SUM(CASE WHEN close < prev_close THEN 1 ELSE 0 END) AS down,
+			SUM(CASE WHEN close = prev_close THEN 1 ELSE 0 END) AS flat
 		`).
 		Where(baseWhere, latestDate, indexSymbolsList()).
 		Scan(&counts).Error; err != nil {
@@ -154,6 +155,84 @@ func (h *StockHandler) TriggerSync(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"success": true, "records_count": count})
 }
 
+type debugStatsResponse struct {
+	TradeDate      string     `json:"trade_date"`
+	Total          int64      `json:"total"`
+	IndexCount     int64      `json:"index_count"`
+	SuspendedCount int64      `json:"suspended_count"`
+	UpByPrice      int64      `json:"up_by_price"`
+	DownByPrice    int64      `json:"down_by_price"`
+	FlatByPrice    int64      `json:"flat_by_price"`
+	UpByPct        int64      `json:"up_by_pct"`
+	DownByPct      int64      `json:"down_by_pct"`
+	FlatByPct      int64      `json:"flat_by_pct"`
+	FlatSamples    []stockRow `json:"flat_samples"`
+	BoundarySamples []stockRow `json:"boundary_samples"`
+}
+
+// DebugStats 返回最新交易日的详细统计与边界样本，便于对齐第三方口径。
+func (h *StockHandler) DebugStats(c *gin.Context) {
+	ctx := context.Background()
+
+	var latestDate time.Time
+	if err := h.DB.WithContext(ctx).Model(&models.StockDailyQuote{}).
+		Select("MAX(trade_date)").Scan(&latestDate).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"success": false, "error": "查询最新交易日失败"})
+		return
+	}
+	if latestDate.IsZero() {
+		c.JSON(http.StatusOK, gin.H{"success": true, "data": debugStatsResponse{}})
+		return
+	}
+
+	idxList := indexSymbolsList()
+	baseWhere := "trade_date = ? AND symbol NOT IN ? AND NOT (volume = 0 AND change_pct = 0)"
+
+	var stats debugStatsResponse
+	h.DB.WithContext(ctx).Model(&models.StockDailyQuote{}).
+		Select(`
+			COUNT(*) AS total,
+			SUM(CASE WHEN close > prev_close THEN 1 ELSE 0 END) AS up_by_price,
+			SUM(CASE WHEN close < prev_close THEN 1 ELSE 0 END) AS down_by_price,
+			SUM(CASE WHEN close = prev_close THEN 1 ELSE 0 END) AS flat_by_price,
+			SUM(CASE WHEN change_pct > 0 THEN 1 ELSE 0 END) AS up_by_pct,
+			SUM(CASE WHEN change_pct < 0 THEN 1 ELSE 0 END) AS down_by_pct,
+			SUM(CASE WHEN change_pct = 0 THEN 1 ELSE 0 END) AS flat_by_pct
+		`).
+		Where(baseWhere, latestDate, idxList).
+		Scan(&stats)
+
+	h.DB.WithContext(ctx).Model(&models.StockDailyQuote{}).
+		Where("trade_date = ? AND symbol IN ?", latestDate, idxList).
+		Count(&stats.IndexCount)
+
+	h.DB.WithContext(ctx).Model(&models.StockDailyQuote{}).
+		Where("trade_date = ? AND symbol NOT IN ? AND volume = 0 AND change_pct = 0", latestDate, idxList).
+		Count(&stats.SuspendedCount)
+
+	stats.TradeDate = latestDate.Format("2006-01-02")
+
+	var flatSamples []stockRow
+	h.DB.WithContext(ctx).Model(&models.StockDailyQuote{}).
+		Select("symbol, name, close, prev_close, change_pct").
+		Where("trade_date = ? AND symbol NOT IN ? AND close = prev_close", latestDate, idxList).
+		Order("amount DESC").
+		Limit(20).
+		Scan(&flatSamples)
+	stats.FlatSamples = flatSamples
+
+	var boundarySamples []stockRow
+	h.DB.WithContext(ctx).Model(&models.StockDailyQuote{}).
+		Select("symbol, name, close, prev_close, change_pct").
+		Where("trade_date = ? AND symbol NOT IN ?", latestDate, idxList).
+		Order("ABS(change_pct) ASC").
+		Limit(20).
+		Scan(&boundarySamples)
+	stats.BoundarySamples = boundarySamples
+
+	c.JSON(http.StatusOK, gin.H{"success": true, "data": stats})
+}
+
 func indexSymbolsList() []string {
 	list := make([]string, 0, len(coreIndexSymbols))
 	for s := range coreIndexSymbols {
diff --git a/backend/internal/routes/routes.go b/backend/internal/routes/routes.go
index 8435729..c1c02f3 100644
--- a/backend/internal/routes/routes.go
+++ b/backend/internal/routes/routes.go
@@ -61,6 +61,7 @@ func Setup(cfg *config.Config, db *gorm.DB, stockSyncSvc *services.StockSyncServ
 		admin.DELETE("/users/:id", adminHandler.DeleteUser)
 		admin.GET("/roles", adminHandler.ListRoles)
 		admin.POST("/stocks/sync", stockHandler.TriggerSync)
+		admin.GET("/stocks/debug-stats", stockHandler.DebugStats)
 	}
 
 	return r