diff --git a/backend/src/main/kotlin/com/wrbug/polymarketbot/service/cryptotail/CryptoTailOrderbookWsService.kt b/backend/src/main/kotlin/com/wrbug/polymarketbot/service/cryptotail/CryptoTailOrderbookWsService.kt
index 7ad37b3..8797df3 100644
--- a/backend/src/main/kotlin/com/wrbug/polymarketbot/service/cryptotail/CryptoTailOrderbookWsService.kt
+++ b/backend/src/main/kotlin/com/wrbug/polymarketbot/service/cryptotail/CryptoTailOrderbookWsService.kt
@@ -10,6 +10,7 @@ import com.wrbug.polymarketbot.service.binance.BinanceKlineAutoSpreadService
 import com.wrbug.polymarketbot.util.RetrofitFactory
 import com.wrbug.polymarketbot.util.createClient
 import com.wrbug.polymarketbot.util.fromJson
+import com.wrbug.polymarketbot.util.gt
 import com.wrbug.polymarketbot.util.toJson
 import com.wrbug.polymarketbot.util.toSafeBigDecimal
 import kotlinx.coroutines.CoroutineScope
@@ -136,8 +137,13 @@ class CryptoTailOrderbookWsService(
                 val assetId = (json.get("asset_id") as? com.google.gson.JsonPrimitive)?.asString ?: return
                 val bids = json.get("bids") as? com.google.gson.JsonArray
                 if (bids == null || bids.isEmpty) return
-                val firstBid = bids.get(0) as? com.google.gson.JsonObject
-                val bestBid = (firstBid?.get("price") as? com.google.gson.JsonPrimitive)?.asString?.toSafeBigDecimal()
+                // Polymarket book 的 bids 为价格升序，bids[0] 为最低买价；bestBid 应取最高买价
+                var bestBid: BigDecimal? = null
+                for (i in 0 until bids.size()) {
+                    val level = bids.get(i) as? com.google.gson.JsonObject ?: continue
+                    val p = (level.get("price") as? com.google.gson.JsonPrimitive)?.asString?.toSafeBigDecimal() ?: continue
+                    if (bestBid == null || p.gt(bestBid)) bestBid = p
+                }
                 if (bestBid != null) onBestBid(assetId, bestBid)
             }
 
@@ -157,10 +163,7 @@ class CryptoTailOrderbookWsService(
     private fun onBestBid(tokenId: String, bestBid: BigDecimal) {
         if (closedForNoStrategies.get()) return
         val entries = tokenToEntries.get()[tokenId]
-        if (entries == null) {
-            logger.debug("tokenToEntries null: $tokenId")
-            return
-        }
+        if (entries == null) return
         val nowSeconds = System.currentTimeMillis() / 1000
         for (e in entries) {
             val windowStart = e.periodStartUnix + e.strategy.windowStartSeconds