Summary
On October 13, 2025, one of our automated risk controls activated during an unusually high wave of fractional buy orders just before the market opened. The control is designed to pause accepting new fractional orders for a short period to keep overall platform risk within preset limits. After the opening bell, the system rebalanced automatically and order acceptance returned to normal.
- This was an operational / availability event related to risk thresholds.
- No security or privacy incident occurred (no data loss, no unauthorized access).
- The issue presented as order rejections, not incorrect executions.
Impact to Customers
- A subset of fractional orders submitted prior to market open were rejected between 9:27 AM and the market opened till 9:31 AM ET.
- There was no ongoing impact after 9:31 AM ET.
Root Cause
- A higher-than-usual concentration of fractional buy orders pushed our risk exposure to a preset limit.
- The platform temporarily stopped accepting new fractional buy orders as a safeguard until risk returned to normal at the open.
Risk Management and Mitigation StrategyCompleted
- Restored and tested alerts that warn well before limits are reached.
- Increased the limit on the relevant risk threshold (without relaxing our overall risk posture).
In Progress
- Earlier pre-open processing to smooth order flow before the bell.
- Dedicated pre-open monitoring so a human can intervene if thresholds approach.
- Pre-open risk adjustments: enabling approved methods to adjust exposure before the open, where appropriate.
Timeline (Eastern Time)
- 9:21 AM — Event window begins.
- ~9:27 AM — Some orders start rejecting due to protective controls.
- 9:31 AM (market open) — System auto-rebalances; normal order acceptance resumes.