At 09:34 ET on 2026-09-28 Alpaca's movers screener returned 'TSX:STC', a
Toronto listing. The discovery filter only dropped symbols containing a dot,
so it joined the universe. The live ingest fetches bars for every symbol in
one batched request, and Alpaca rejects the WHOLE batch with 400 "invalid
symbol". From 09:35 every ingest pass stored 0 rows and the loop ran on
stale bars ("INGEST STALE: freshest bar 458s old").
- Discovery keeps only plain 1-5 letter US tickers from both screeners.
- The ingest never sends a non-US or invalid symbol. If Alpaca still rejects
one ("invalid symbol: X"), it drops X and retries the rest (up to 3 times),
so one bad name costs one symbol, not the session.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E3S5EFKThFVrjmN4HHsHMN
