write_features_bulk writes many symbols in a single transaction (one fsync/checkpoint vs one per symbol); ingest_crypto_pit collects all 155 symbols then one bulk call. Equivalence test proves identical result. Targets the ~52min nightly crypto ingest in the Dagster combined-book run. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>