diff --git a/services/aggregation/main.py b/services/aggregation/main.py
index f1e564c..0fd2e7f 100644
--- a/services/aggregation/main.py
+++ b/services/aggregation/main.py
@@ -177,9 +177,15 @@ async def main() -> None:
                             ticker,
                         )
 
-                # Enqueue recommendation job for each window that produced a trend
+                # Enqueue recommendation job for each window that produced a trend.
+                # Use Redis dedup to avoid flooding the recommendation queue
+                # with duplicate ticker+window jobs that haven't been processed yet.
                 for summary in summaries:
                     if summary.trend_strength > 0:
+                        dedup_key = f"stonks:rec_dedup:{ticker}:{summary.window.value}"
+                        already = await redis_client.get(dedup_key)
+                        if already:
+                            continue
                         await redis_client.rpush(
                             rec_queue,
                             json.dumps(inject_trace_context({
@@ -187,6 +193,9 @@ async def main() -> None:
                                 "window": summary.window.value,
                             })),
                         )
+                        # Mark as enqueued for 5 minutes — enough time for
+                        # the recommendation worker to process it.
+                        await redis_client.set(dedup_key, "1", ex=300)
             except Exception:
                 logger.exception("Aggregation failed for %s", ticker)
     finally: