diff --git a/app/scheduler.py b/app/scheduler.py
index 6322b4e..ed1fd1a 100644
--- a/app/scheduler.py
+++ b/app/scheduler.py
@@ -41,8 +41,22 @@ from app.services.ticker_universe_service import bootstrap_universe
 
 logger = logging.getLogger(__name__)
 
-# Module-level scheduler instance
-scheduler = AsyncIOScheduler()
+# Module-level scheduler instance.
+#
+# job_defaults matter a lot here: this is a single-process app, so the scheduler
+# shares one event loop with the API and every other job. APScheduler's default
+# misfire_grace_time is just 1 second — if the loop is busy at the instant a
+# daily job is due (e.g. the scanner is mid-run), the fire is processed late,
+# flagged a misfire, and SILENTLY SKIPPED while next_run still advances 24h. So
+# we grant a generous grace window, coalesce missed runs into one catch-up, and
+# cap each job at a single concurrent instance.
+scheduler = AsyncIOScheduler(
+    job_defaults={
+        "coalesce": True,
+        "max_instances": 1,
+        "misfire_grace_time": 3600,  # tolerate a busy loop; a daily job up to 1h late is fine
+    }
+)
 
 # Track last successful ticker per job for rate-limit resume
 _last_successful: dict[str, str | None] = {