feat: ticker validation + SLV/USO/WEAT/CORN/TUR added to ETFs watchlist

Backend:
- GET /api/market/validate?symbol= — validates ticker against yfinance,
  returns {valid, name, price} or {valid: false, reason: 'helpful message'}
- Added SLV, USO, WEAT, CORN, TUR to ETFs WATCHLIST category

Frontend:
- validateTicker() async helper exported from useApi.ts
- InstrumentPicker (PatternLab): custom ticker field now validates before selecting
  Shows spinner while checking, red error message if not found on yfinance
- InstrumentLens (PatternExplorer): same validation on Go button + Enter key

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/routers/market_data.py

@@ -39,6 +39,24 @@ def watchlist():
     return WATCHLIST
 
 
+@router.get("/validate")
+def validate_ticker(symbol: str = Query(..., description="Ticker to validate against yfinance")):
+    """Check if a ticker is fetchable. Returns valid=True + live price/name, or valid=False + reason."""
+    from services.data_fetcher import get_quote
+    import yfinance as yf
+    symbol = symbol.strip().upper()
+    q = get_quote(symbol)
+    if q and q.get("price"):
+        # Try to get a display name
+        try:
+            info = yf.Ticker(symbol).fast_info
+            name = getattr(info, "long_name", None) or getattr(info, "short_name", None) or symbol
+        except Exception:
+            name = symbol
+        return {"valid": True, "symbol": symbol, "name": name, "price": q["price"], "change_pct": q.get("change_pct")}
+    return {"valid": False, "symbol": symbol, "reason": f"Ticker '{symbol}' not found on yfinance — check the symbol (e.g. GC=F for Gold, ^GSPC for S&P 500)"}
+
+
 @router.get("/macro-regime")
 def macro_regime(force: bool = False):
     """Macro gauge values + 5-scenario scoring. Cached 15 min."""

backend/services/data_fetcher.py

@@ -56,24 +56,29 @@ WATCHLIST: Dict[str, List[Dict[str, str]]] = {
         {"symbol": "^VIX", "name": "VIX Volatility", "currency": "USD"},
     ],
     "etfs": [
-        {"symbol": "SPY",  "name": "S&P 500 ETF (SPY)",      "currency": "USD"},
+        {"symbol": "SPY",  "name": "S&P 500 ETF (SPY)",        "currency": "USD"},
-        {"symbol": "QQQ",  "name": "NASDAQ 100 ETF (QQQ)",   "currency": "USD"},
+        {"symbol": "QQQ",  "name": "NASDAQ 100 ETF (QQQ)",     "currency": "USD"},
-        {"symbol": "IWM",  "name": "Russell 2000 ETF (IWM)", "currency": "USD"},
+        {"symbol": "IWM",  "name": "Russell 2000 ETF (IWM)",   "currency": "USD"},
-        {"symbol": "TLT",  "name": "20Y Treasury ETF (TLT)", "currency": "USD"},
+        {"symbol": "TLT",  "name": "20Y Treasury ETF (TLT)",   "currency": "USD"},
-        {"symbol": "IEF",  "name": "7-10Y Treasury ETF (IEF)","currency": "USD"},
+        {"symbol": "IEF",  "name": "7-10Y Treasury ETF (IEF)", "currency": "USD"},
-        {"symbol": "HYG",  "name": "High Yield Bond (HYG)",  "currency": "USD"},
+        {"symbol": "HYG",  "name": "High Yield Bond (HYG)",    "currency": "USD"},
-        {"symbol": "GLD",  "name": "Gold ETF (GLD)",         "currency": "USD"},
+        {"symbol": "GLD",  "name": "Gold ETF (GLD)",           "currency": "USD"},
-        {"symbol": "EEM",  "name": "EM ETF (EEM)",           "currency": "USD"},
+        {"symbol": "SLV",  "name": "Silver ETF (SLV)",         "currency": "USD"},
-        {"symbol": "FXI",  "name": "China Large Cap (FXI)",  "currency": "USD"},
+        {"symbol": "USO",  "name": "Oil ETF (USO)",            "currency": "USD"},
-        {"symbol": "EWG",  "name": "Germany ETF (EWG)",      "currency": "USD"},
+        {"symbol": "EEM",  "name": "EM ETF (EEM)",             "currency": "USD"},
-        {"symbol": "EWJ",  "name": "Japan ETF (EWJ)",        "currency": "USD"},
+        {"symbol": "FXI",  "name": "China Large Cap (FXI)",    "currency": "USD"},
-        {"symbol": "EWU",  "name": "UK ETF (EWU)",           "currency": "USD"},
+        {"symbol": "EWG",  "name": "Germany ETF (EWG)",        "currency": "USD"},
-        {"symbol": "EWZ",  "name": "Brazil ETF (EWZ)",       "currency": "USD"},
+        {"symbol": "EWJ",  "name": "Japan ETF (EWJ)",          "currency": "USD"},
-        {"symbol": "XLF",  "name": "Financials ETF (XLF)",   "currency": "USD"},
+        {"symbol": "EWU",  "name": "UK ETF (EWU)",             "currency": "USD"},
-        {"symbol": "SMH",  "name": "Semiconductors (SMH)",   "currency": "USD"},
+        {"symbol": "EWZ",  "name": "Brazil ETF (EWZ)",         "currency": "USD"},
-        {"symbol": "KWEB", "name": "China Internet (KWEB)",  "currency": "USD"},
+        {"symbol": "XLF",  "name": "Financials ETF (XLF)",     "currency": "USD"},
-        {"symbol": "UUP",  "name": "US Dollar ETF (UUP)",    "currency": "USD"},
+        {"symbol": "SMH",  "name": "Semiconductors (SMH)",     "currency": "USD"},
-        {"symbol": "BIL",  "name": "T-Bill 1-3M (BIL)",     "currency": "USD"},
+        {"symbol": "KWEB", "name": "China Internet (KWEB)",    "currency": "USD"},
+        {"symbol": "UUP",  "name": "US Dollar ETF (UUP)",      "currency": "USD"},
+        {"symbol": "BIL",  "name": "T-Bill 1-3M (BIL)",       "currency": "USD"},
+        {"symbol": "TUR",  "name": "Turkey ETF (TUR)",         "currency": "USD"},
+        {"symbol": "WEAT", "name": "Wheat ETF (WEAT)",         "currency": "USD"},
+        {"symbol": "CORN", "name": "Corn ETF (CORN)",          "currency": "USD"},
     ],
     "equities": [
         {"symbol": "XOM", "name": "Exxon Mobil", "currency": "USD"},

frontend/src/hooks/useApi.ts

@@ -16,6 +16,10 @@ export const useAllQuotes = () =>
     refetchInterval: 60_000,
   })
 
+export type TickerValidation = { valid: boolean; symbol: string; name?: string; price?: number; change_pct?: number; reason?: string }
+export const validateTicker = (symbol: string): Promise<TickerValidation> =>
+  api.get('/market/validate', { params: { symbol } }).then(r => r.data)
+
 export const useHistory = (symbol: string, period = '1y', interval = '1d') =>
   useQuery<HistoricalCandle[]>({
     queryKey: ['history', symbol, period, interval],

frontend/src/pages/PatternExplorer.tsx

@@ -3,13 +3,14 @@ import { Link } from 'react-router-dom'
 import clsx from 'clsx'
 import {
   TreePine, Search, ChevronRight, ChevronDown,
-  TrendingUp, TrendingDown, Zap, BookOpen, ExternalLink,
+  TrendingUp, TrendingDown, Zap, BookOpen, ExternalLink, RefreshCw,
 } from 'lucide-react'
 import {
   useAllPatterns,
   usePatternTaxonomy,
   usePatternsByInstrument,
   useLastScores,
+  validateTicker,
 } from '../hooks/useApi'
 import { INSTRUMENTS, INSTRUMENT_CATEGORIES } from '../constants/instruments'
 
@@ -591,7 +592,9 @@ function InstrumentRow({ pattern, searchTerm }: { pattern: Pattern; searchTerm:
 function InstrumentLens({ patterns }: { patterns: Pattern[] }) {
   const [searchTerm, setSearchTerm]     = useState('')
   const [activeCategory, setActiveCategory] = useState<string | null>(null)
-  const [customInput, setCustomInput]   = useState('')
+  const [customInput, setCustomInput]     = useState('')
+  const [validating, setValidating]       = useState(false)
+  const [tickerError, setTickerError]     = useState<string | null>(null)
   const debounceRef = useRef<ReturnType<typeof setTimeout> | null>(null)
 
   // Selected ticker — either clicked from grid or typed
@@ -629,9 +632,24 @@ function InstrumentLens({ patterns }: { patterns: Pattern[] }) {
     )
   }, [uniqueInstruments, activeCategory, searchTerm])
 
-  const handleCustom = () => {
+  const handleCustom = async () => {
-    const t = customInput.trim()
+    const sym = customInput.trim().toUpperCase()
-    if (t) { setSelectedTicker(t); setCustomInput('') }
+    if (!sym) return
+    setTickerError(null)
+    setValidating(true)
+    try {
+      const res = await validateTicker(sym)
+      if (res.valid) {
+        setSelectedTicker(sym)
+        setCustomInput('')
+      } else {
+        setTickerError(res.reason || `Ticker '${sym}' not found`)
+      }
+    } catch {
+      setTickerError(`Could not validate '${sym}' — check your connection`)
+    } finally {
+      setValidating(false)
+    }
   }
 
   return (
@@ -660,12 +678,25 @@ function InstrumentLens({ patterns }: { patterns: Pattern[] }) {
             placeholder="Search instruments…"
             className="w-full pl-8 pr-3 py-1.5 text-xs bg-dark-700 border border-slate-700/50 rounded text-slate-200 placeholder-slate-600 focus:outline-none focus:border-blue-600" />
         </div>
-        <input type="text" value={customInput} onChange={e => setCustomInput(e.target.value)}
+        <div className="flex flex-col gap-1">
-          onKeyDown={e => e.key === 'Enter' && handleCustom()}
+          <div className="flex gap-1">
-          placeholder="Custom ticker…"
+            <input type="text" value={customInput}
-          className="w-32 px-2 py-1.5 text-xs bg-dark-700 border border-slate-700/50 rounded text-slate-200 placeholder-slate-600 focus:outline-none focus:border-blue-600 font-mono" />
+              onChange={e => { setCustomInput(e.target.value); setTickerError(null) }}
-        <button onClick={handleCustom}
+              onKeyDown={e => e.key === 'Enter' && handleCustom()}
-          className="px-2.5 py-1.5 text-xs bg-blue-700 hover:bg-blue-600 text-white rounded transition-colors">Go</button>
+              placeholder="Custom ticker…"
+              className={clsx(
+                'w-32 px-2 py-1.5 text-xs bg-dark-700 border rounded text-slate-200 placeholder-slate-600 focus:outline-none font-mono uppercase',
+                tickerError ? 'border-red-500/70 focus:border-red-400' : 'border-slate-700/50 focus:border-blue-600'
+              )} />
+            <button onClick={handleCustom} disabled={!customInput.trim() || validating}
+              className="px-2.5 py-1.5 text-xs bg-blue-700 hover:bg-blue-600 disabled:opacity-40 text-white rounded transition-colors flex items-center gap-1">
+              {validating ? <><RefreshCw className="w-3 h-3 animate-spin" /> …</> : 'Go'}
+            </button>
+          </div>
+          {tickerError && (
+            <p className="text-[9px] text-red-400 max-w-[200px] leading-tight">{tickerError}</p>
+          )}
+        </div>
         {selectedTicker && (
           <button onClick={() => setSelectedTicker('')}
             className="text-xs text-slate-500 hover:text-slate-300 transition-colors">Clear</button>

frontend/src/pages/PatternLab.tsx

@@ -3,6 +3,7 @@ import {
   useRunPatternLab, useEvaluatePatternLab, useSaveLabPattern,
   usePatternLabRuns, useDeleteLabRun,
   useInstrumentScan, useEvaluateInstrumentScan,
+  validateTicker,
 } from '../hooks/useApi'
 import {
   FlaskConical, Play, CheckCircle2, XCircle, MinusCircle,
@@ -146,9 +147,11 @@ function OutcomeRow({ out }: { out: any }) {
 // ── Shared instrument picker ───────────────────────────────────────────────────
 
 function InstrumentPicker({ onSelect }: { onSelect: (ticker: string, name: string) => void }) {
-  const [search, setSearch] = useState('')
+  const [search, setSearch]         = useState('')
-  const [cat, setCat]       = useState<string | null>(null)
+  const [cat, setCat]               = useState<string | null>(null)
-  const [custom, setCustom] = useState('')
+  const [custom, setCustom]         = useState('')
+  const [validating, setValidating] = useState(false)
+  const [tickerError, setTickerError] = useState<string | null>(null)
 
   const seen = new Set<string>()
   const unique = INSTRUMENTS.filter(i => { if (seen.has(i.ticker)) return false; seen.add(i.ticker); return true })
@@ -162,6 +165,26 @@ function InstrumentPicker({ onSelect }: { onSelect: (ticker: string, name: strin
     return true
   })
 
+  const handleCustom = async () => {
+    const sym = custom.trim().toUpperCase()
+    if (!sym) return
+    setTickerError(null)
+    setValidating(true)
+    try {
+      const res = await validateTicker(sym)
+      if (res.valid) {
+        onSelect(sym, res.name || sym)
+        setCustom('')
+      } else {
+        setTickerError(res.reason || `Ticker '${sym}' not found`)
+      }
+    } catch {
+      setTickerError(`Could not validate '${sym}' — check your connection`)
+    } finally {
+      setValidating(false)
+    }
+  }
+
   return (
     <div className="space-y-2">
       {/* Category pills */}
@@ -186,10 +209,24 @@ function InstrumentPicker({ onSelect }: { onSelect: (ticker: string, name: strin
           <input value={search} onChange={e => setSearch(e.target.value)} placeholder="Search…"
             className="w-full pl-6 pr-2 py-1.5 text-xs bg-dark-700 border border-slate-700/50 rounded text-slate-200 placeholder-slate-600 focus:outline-none focus:border-violet-500" />
         </div>
-        <input value={custom} onChange={e => setCustom(e.target.value)}
+        <div className="flex flex-col gap-1">
-          onKeyDown={e => e.key === 'Enter' && custom.trim() && onSelect(custom.trim(), custom.trim())}
+          <div className="flex gap-1">
-          placeholder="Custom ticker"
+            <input value={custom} onChange={e => { setCustom(e.target.value); setTickerError(null) }}
-          className="w-28 px-2 py-1.5 text-xs bg-dark-700 border border-slate-700/50 rounded font-mono text-slate-200 placeholder-slate-600 focus:outline-none focus:border-violet-500" />
+              onKeyDown={e => e.key === 'Enter' && handleCustom()}
+              placeholder="Custom ticker"
+              className={clsx(
+                'w-28 px-2 py-1.5 text-xs bg-dark-700 border rounded font-mono text-slate-200 placeholder-slate-600 focus:outline-none uppercase',
+                tickerError ? 'border-red-500/70 focus:border-red-400' : 'border-slate-700/50 focus:border-violet-500'
+              )} />
+            <button onClick={handleCustom} disabled={!custom.trim() || validating}
+              className="px-2 py-1.5 text-xs bg-dark-700 border border-slate-700/50 rounded text-slate-400 hover:text-slate-200 hover:border-violet-500 disabled:opacity-40 transition-colors">
+              {validating ? <RefreshCw className="w-3 h-3 animate-spin" /> : '→'}
+            </button>
+          </div>
+          {tickerError && (
+            <p className="text-[9px] text-red-400 max-w-[140px] leading-tight">{tickerError}</p>
+          )}
+        </div>
       </div>
       {/* Grid */}
       <div className="grid grid-cols-3 gap-1 max-h-60 overflow-y-auto pr-1">