diff --git a/backend/src/routes/options.ts b/backend/src/routes/options.ts
index 9125ece..16ecf7a 100644
--- a/backend/src/routes/options.ts
+++ b/backend/src/routes/options.ts
@@ -526,15 +526,26 @@ optionsRouter.delete("/orders/:id", (c) => {
 // HV30 and IV/HV ratio for each. Highlight spikes where IV >> HV.
 // ---------------------------------------------------------------------------
 const DEFAULT_SCAN_SYMBOLS = [
-  "SPY","QQQ","IWM","DIA",
+  // Indices & sector ETFs (8) — vol-stable references
+  "SPY","QQQ","IWM","DIA","SMH","XLF","XLE","XLK",
+  // Mega-cap tech (6)
   "AAPL","MSFT","NVDA","GOOGL","META","AMZN",
-  "TSLA","AMD","NFLX","COIN","INTC",
+  // Semiconductors (5) — frequent earnings & policy catalysts
+  "AMD","INTC","TSM","AVGO","MU",
+  // High-vol / event-driven (7)
+  "TSLA","NFLX","COIN","PLTR","SHOP","UBER","MARA",
+  // Financials (4)
+  "JPM","BAC","GS","V",
+  // Healthcare (3)
+  "LLY","JNJ","UNH",
+  // Consumer / energy (4)
+  "XOM","WMT","DIS","MCD",
 ];
 
 optionsRouter.get("/scan", async (c) => {
   const symsParam = c.req.query("symbols");
   const symbols = (symsParam ? symsParam.split(",") : DEFAULT_SCAN_SYMBOLS)
-    .map((s) => s.trim().toUpperCase()).filter(Boolean).slice(0, 30);
+    .map((s) => s.trim().toUpperCase()).filter(Boolean).slice(0, 100);
 
   if (symbols.length === 0) return c.json(fail("No symbols to scan"), 400);
 
diff --git a/frontend/scanner.html b/frontend/scanner.html
index 78bdbb2..37cd35c 100644
--- a/frontend/scanner.html
+++ b/frontend/scanner.html
@@ -216,7 +216,24 @@
   <script src="/assets/alpine.min.js" defer></script>
 
   <script>
-    const DEFAULT_SYMBOLS = ["SPY","QQQ","IWM","DIA","AAPL","MSFT","NVDA","GOOGL","META","AMZN","TSLA","AMD","NFLX","COIN","INTC"];
+    // Curated default watchlist (~37 names) — sector-diversified, all optionable mid+ cap.
+    // Backend caps custom lists at 100 symbols.
+    const DEFAULT_SYMBOLS = [
+      // Indices & sector ETFs
+      "SPY","QQQ","IWM","DIA","SMH","XLF","XLE","XLK",
+      // Mega-cap tech
+      "AAPL","MSFT","NVDA","GOOGL","META","AMZN",
+      // Semiconductors
+      "AMD","INTC","TSM","AVGO","MU",
+      // High-vol / event-driven
+      "TSLA","NFLX","COIN","PLTR","SHOP","UBER","MARA",
+      // Financials
+      "JPM","BAC","GS","V",
+      // Healthcare
+      "LLY","JNJ","UNH",
+      // Consumer / energy
+      "XOM","WMT","DIS","MCD",
+    ];
 
     function scannerApp() {
       return {