In practice, it happens extremely rarely when users can't place new orders on the platform. Though, the matching engine may need to restart for several reasons. When a restart occurs, the matching engine goes into a Cancel-only Mode.
It means that:
- Traders cannot place new Orders.
- Traders are able to cancel open Orders.
- No Orders will be filled.
- Attempt to place orders while in Cancel-only Mode will be automatically cancelled.
Matching engine will stay in Cancel-only Mode for 5 minutes after restart. A restart can happen at any time without warning. Please be patient when it occurs.