--- a/place_bet.py
+++ b/place_bet.py
@@ -28,14 +28,18 @@
 CLOB_HOST = "https://clob.polymarket.com"
 GAMMA_API = "https://gamma-api.polymarket.com"
 CHAIN_ID = POLYGON
-WINDOW_SECONDS = 300  # 5-minute windows
+
+MARKETS = {
+    "5m":  {"window": 300,  "prefix": "btc-updown-5m"},
+    "15m": {"window": 900,  "prefix": "btc-updown-15m"},
+}
 
 
 # ── Helpers ──────────────────────────────────────────────────────────────────
 
 
-def current_slug() -> str:
-    ts = int(time.time())
-    window_ts = (ts // WINDOW_SECONDS) * WINDOW_SECONDS
-    return f"btc-updown-5m-{window_ts}"
+def current_slug(market: str) -> str:
+    cfg = MARKETS[market]
+    ts = int(time.time())
+    window_ts = (ts // cfg["window"]) * cfg["window"]
+    return f"{cfg['prefix']}-{window_ts}"
 
 
 def resolve_tokens(slug: str) -> dict[str, str]:
@@ -107,6 +111,13 @@
         type=float,
         help="Dollar amount to bet",
     )
+    parser.add_argument(
+        "--market",
+        required=False,
+        default="5m",
+        choices=["5m", "15m"],
+        help="Market window size (default: 5m)",
+    )
     parser.add_argument(
         "--dry-run",
         action="store_true",
@@ -116,12 +127,13 @@
 
     direction = args.direction
     amount = args.amount
+    market = args.market
     dry_run = args.dry_run
 
     result = {}
 
     try:
-        # 1. Slug
-        slug = current_slug()
+        slug = current_slug(market)
         result["slug"] = slug
+        result["market"] = market
 
         # 2. Tokens