Velocity Logic is a safety mechanism used by the CME Group to help stabilize markets during periods of extreme volatility. If prices move too far, too fast, the CME matching engine(s) can briefly pause trading across all platforms to prevent erratic price swings.
How It Works
The system continuously monitors price movement for all CME products.
If a product’s price moves beyond a set threshold within milliseconds, a brief pause is triggered.
When that happens, the market enters a temporary “Pre-Open” state, where:
Order entry, modification, and cancellation are allowed
No trades are executed
Temporary order rejection alerts may appear on your platform
After a short pause (~5 seconds), the market resumes normal trading.
Benefits of Velocity Logic:
Keep markets more stable during high volatility
Give traders a chance to adjust their strategies
Prevent rapid price swings that can cause unexpected losses
Velocity Logic impacts all CME products across all trading platforms, but the TopstepX platform alerts traders in real time when a Velocity Logic pause is active. Not all platforms provide this type of alerting.
For more details, read the CME Group’s explanation: Understanding Velocity Logic