diff --git a/manual_trading_hub/static/chart.js b/manual_trading_hub/static/chart.js
index a563eb2..1230d0a 100644
--- a/manual_trading_hub/static/chart.js
+++ b/manual_trading_hub/static/chart.js
@@ -3,7 +3,7 @@
  */
 (function () {
   const CHART_WATCH_HEARTBEAT_MS = 25000;
-  const CHART_SSE_FALLBACK_MS = 60000;
+  const CHART_SSE_FALLBACK_MS = 15000;
   const DEFAULT_VISIBLE_BARS = 200;
   const CHART_LOAD_LEFT_THRESHOLD = 25;
   const CHART_INITIAL_LIMITS = {
@@ -2312,7 +2312,21 @@
   }
 
   function viewKey(exKey, sym, tf) {
-    return (exKey || "") + "|" + (sym || "") + "|" + (tf || "");
+    const ex = String(exKey || "").trim().toLowerCase();
+    const s = normalizeMarketSymbol(sym);
+    const t = String(tf || "").trim();
+    return ex + "|" + s + "|" + t;
+  }
+
+  function lookupSeriesMapEntry(map, vKey) {
+    if (!map || !vKey) return null;
+    if (map[vKey]) return map[vKey];
+    const parts = String(vKey).split("|");
+    if (parts.length === 3) {
+      const norm = viewKey(parts[0], parts[1], parts[2]);
+      if (norm !== vKey && map[norm]) return map[norm];
+    }
+    return null;
   }
 
   function chartInitialLimit(tf) {
@@ -2773,10 +2787,10 @@
 
   function currentViewSeriesKey() {
     const exKey = (elExchange && elExchange.value) || "";
-    const sym = (elSymbol && elSymbol.value.trim().toUpperCase()) || "";
+    const sym = (elSymbol && elSymbol.value.trim()) || "";
     const tf = (elTf && elTf.value) || "1d";
     if (!exKey || !sym) return "";
-    return exKey + "|" + sym + "|" + tf;
+    return viewKey(exKey, sym, tf);
   }
 
   function postChartWatch() {
@@ -2812,6 +2826,45 @@
     }
   }
 
+  function handleChartStreamEvent(st) {
+    if (!st || st.polling) return;
+    const vKey = currentViewSeriesKey();
+    if (!vKey) return;
+    const tails = st.tails || {};
+    const series = st.series || {};
+    const tailPack = lookupSeriesMapEntry(tails, vKey);
+    if (tailPack && tailPack.candles && tailPack.candles.length) {
+      if (
+        applyIncomingTailCandles(tailPack.candles, {
+          price_tick: tailPack.price_tick,
+          series_version: tailPack.series_version,
+          chart_version: st.chart_version,
+          updated_at: tailPack.updated_at || st.updated_at,
+        })
+      ) {
+        return;
+      }
+    }
+    const seriesEntry = lookupSeriesMapEntry(series, vKey);
+    const sVer = seriesEntry ? Number(seriesEntry.series_version) || 0 : 0;
+    const seriesChanged = sVer > 0 && sVer !== localSeriesVersion;
+    if (seriesChanged) {
+      if (lastCandles.length && vKey === lastViewKey) {
+        void refreshChartTail();
+      } else if (!lastCandles.length && !chartDataLoading) {
+        void loadChart(false);
+      }
+      return;
+    }
+    if (tailPack && lastCandles.length && vKey === lastViewKey && !chartDataLoading) {
+      void refreshChartTail();
+      return;
+    }
+    if (posContext) updateLivePosPnl();
+    const ver = Number(st.chart_version) || 0;
+    if (ver && ver !== localChartVersion) localChartVersion = ver;
+  }
+
   function connectChartStream() {
     closeChartStream();
     const page = document.getElementById("page-market");
@@ -2819,34 +2872,7 @@
     chartEventSource = new EventSource("/api/chart/stream");
     chartEventSource.addEventListener("chart", function (ev) {
       try {
-        const st = JSON.parse(ev.data || "{}");
-        if (st.polling) return;
-        const ver = Number(st.chart_version) || 0;
-        const series = st.series || {};
-        const vKey = currentViewSeriesKey();
-        const tails = st.tails || {};
-        const tailPack = vKey && tails[vKey] ? tails[vKey] : null;
-        if (tailPack && tailPack.candles && tailPack.candles.length) {
-          if (
-            applyIncomingTailCandles(tailPack.candles, {
-              price_tick: tailPack.price_tick,
-              series_version: tailPack.series_version,
-              chart_version: ver,
-              updated_at: tailPack.updated_at || st.updated_at,
-            })
-          ) {
-            return;
-          }
-        }
-        const sVer = vKey && series[vKey] ? Number(series[vKey].series_version) || 0 : 0;
-        const seriesChanged = vKey && sVer > 0 && sVer !== localSeriesVersion;
-        if (seriesChanged) {
-          refreshChartTail();
-        } else if (posContext) {
-          updateLivePosPnl();
-        } else if (ver !== localChartVersion) {
-          localChartVersion = ver;
-        }
+        handleChartStreamEvent(JSON.parse(ev.data || "{}"));
       } catch (_) {}
     });
     chartEventSource.onerror = function () {
@@ -2876,11 +2902,17 @@
 
   function startAutoRefresh() {
     stopAutoRefresh();
-    refreshTimer = setInterval(function () {
+    const tick = function () {
       const page = document.getElementById("page-market");
       if (!page || page.classList.contains("hidden")) return;
-      refreshChartTail();
-    }, CHART_SSE_FALLBACK_MS);
+      if (lastCandles.length) {
+        void refreshChartTail();
+      } else if (!chartDataLoading) {
+        void loadChart(false);
+      }
+    };
+    refreshTimer = setInterval(tick, CHART_SSE_FALLBACK_MS);
+    tick();
   }
 
   function stopAutoRefresh() {
@@ -3189,6 +3221,9 @@
       elSymbol.addEventListener("keydown", function (e) {
         if (e.key === "Enter") loadChart(false);
       });
+      elSymbol.addEventListener("change", function () {
+        loadChart(false);
+      });
     }
     const btnLoad = document.getElementById("market-load");
     if (btnLoad) {
diff --git a/manual_trading_hub/static/index.html b/manual_trading_hub/static/index.html
index d1203ef..8f317c8 100644
--- a/manual_trading_hub/static/index.html
+++ b/manual_trading_hub/static/index.html
@@ -1046,7 +1046,7 @@
   <div id="toast"></div>
   <script src="https://unpkg.com/lightweight-charts@4.2.0/dist/lightweight-charts.standalone.production.js"></script>
   <script src="/assets/chart_draw.js?v=20260609-market-day-split"></script>
-  <script src="/assets/chart.js?v=20260609-prev-day-lines"></script>
+  <script src="/assets/chart.js?v=20260614-market-live"></script>
   <script src="/assets/plan.js?v=20260614-plan-refresh"></script>
   <script src="/assets/calculator.js?v=3"></script>
   <script src="/assets/archive.js?v=20260612-archive-ai-chat"></script>