diff --git a/src/backend/app/api/simulate.py b/src/backend/app/api/simulate.py
index 82e087f..0280add 100644
--- a/src/backend/app/api/simulate.py
+++ b/src/backend/app/api/simulate.py
@@ -154,9 +154,17 @@ async def start_simulation(
     # Fetch klines SYNCHRONOUSLY so user can see chart immediately
     try:
         token_id = f"{config.token}-{config.chain}"
+        
+        # Calculate time range (last 1 hour)
+        import time
+        end_time = int(time.time() * 1000)
+        start_time = end_time - (60 * 60 * 1000)  # 1 hour ago
+        
         klines_data = await ave_client.get_klines(
             token_id,
             interval=config.kline_interval,
+            start_time=start_time,
+            end_time=end_time,
             limit=500
         )
         klines_for_chart = [
diff --git a/src/frontend/src/lib/components/SignalChart.svelte b/src/frontend/src/lib/components/SignalChart.svelte
index b6c7dd6..2f2b71e 100644
--- a/src/frontend/src/lib/components/SignalChart.svelte
+++ b/src/frontend/src/lib/components/SignalChart.svelte
@@ -41,12 +41,14 @@
 		// Clear
 		ctx.clearRect(0, 0, width, height);
 
-		// Get price data
-		const prices = klines.length > 0 
-			? klines.map(k => k.close)
-			: signals.map(s => s.price);
+		// Get price data (convert strings to numbers)
+		const priceData = klines.length > 0 
+			? klines.map(k => ({ time: k.time, price: parseFloat(k.close) || 0 }))
+			: signals.map(s => ({ time: 0, price: s.price }));
 		
-		if (prices.length === 0) return;
+		if (priceData.length === 0) return;
+
+		const prices = priceData.map(d => d.price);
 
 		const padding = { top: 20, right: 20, bottom: 30, left: 60 };
 		const chartWidth = width - padding.left - padding.right;