Alpaca incident

Order rejections at pre-market session open

Resolved on August 20, 2026.

resolved Aug 20, 2026, 11:36 AM UTC

On August 20, 2026, a subset of equity orders submitted during the early pre-market session were rejected between approximately 4:00 AM and 4:01 AM ET. A configuration change applied ahead of the session caused the affected orders to be rejected at the time of submission. Rejected orders were not executed. Account balances, positions, and existing holdings were unaffected, and market data and all other platform services operated normally. Regular market hours trading was not impacted. We identified the cause and reverted the change, and order processing returned to normal by approximately 5:25 AM ET. Any affected orders can be resubmitted. We are adding additional validation and monitoring for pre-market changes of this type and moving to a more gradual rollout process to reduce the likelihood of recurrence. We apologize for the disruption.

Started
Aug 20, 2026, 08:00 AM UTC
Resolved
Aug 20, 2026, 08:00 AM UTC
Duration
–
Detected by Pingoru
Aug 20, 2026, 08:00 AM UTC

Update timeline

  1. resolved Aug 20, 2026, 11:36 AM UTC

    On August 20, 2026, a subset of equity orders submitted during the early pre-market session were rejected between approximately 4:00 AM and 4:01 AM ET. A configuration change applied ahead of the session caused the affected orders to be rejected at the time of submission. Rejected orders were not executed. Account balances, positions, and existing holdings were unaffected, and market data and all other platform services operated normally. Regular market hours trading was not impacted. We identified the cause and reverted the change, and order processing returned to normal by approximately 5:25 AM ET. Any affected orders can be resubmitted. We are adding additional validation and monitoring for pre-market changes of this type and moving to a more gradual rollout process to reduce the likelihood of recurrence. We apologize for the disruption.

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