diff --git a/src/oneshot.js b/src/oneshot.js
index 652a387..d9189f9 100644
--- a/src/oneshot.js
+++ b/src/oneshot.js
@@ -175,6 +175,13 @@ async function onSignal(evt) {
     // Only enter from IDLE — one position per market slot
     if (!sm.is(State.IDLE)) return;
 
+    // Global position limit: never open a new position while any other market
+    // is still being held. The engine is designed to focus on one bet at a time.
+    if (posEngine.hasAnyPosition()) {
+        dbg('SIGNAL', `${marketSlug} | blocked — position already open in another market`);
+        return;
+    }
+
     // ── Risk gate ─────────────────────────────────────────────────────────
 
     const riskCheck = riskEngine.canTrade();
diff --git a/src/oneshot/PositionEngine.js b/src/oneshot/PositionEngine.js
index bbad5a3..912f23a 100644
--- a/src/oneshot/PositionEngine.js
+++ b/src/oneshot/PositionEngine.js
@@ -68,6 +68,11 @@ export class PositionEngine {
         return this._positions.has(marketSlug);
     }
 
+    /** True if ANY position is open across all tracked markets */
+    hasAnyPosition() {
+        return this._positions.size > 0;
+    }
+
     /**
      * Close the position actively (adverse-move emergency exit) and return exit data.
      *