The CME Group uses two safeguards to manage extreme market conditions: Price Limits and Velocity Logic.
Price Limits are maximum allowable price moves within a session for certain instruments (typically equity index futures). When a price limit is reached, trading may be halted for a short cool-down period, after which limits may expand or trading resumes.
Velocity Logic is a CME mechanism that detects unusually fast price movements over a very short period and triggers a brief pause (typically 5-30 seconds) on the affected instrument. This prevents disorderly trading during sudden volatility events.
What this means for you on MILTRADERS: Your orders may be temporarily rejected or paused during a velocity event. Open positions are not automatically closed, but you may be unable to enter or exit during the pause. Once the pause ends, normal trading resumes.
Velocity events are rare and usually last only seconds. If you experience repeated rejections during a velocity event, simply wait for the pause to lift before placing new orders.