You receive a US$1 return per contract if your prediction is correct and nothing if it is incorrect.
This market resolves based on the change in basis points to the target federal funds rate, compared to its level before a given Federal Reserve's meeting.
The official resolution source is the FOMC’s published rate data: https://www.federalreserve.gov/monetarypolicy/openmarket.htm
Liquidity may be low during the FOMC meeting. Trading is temporarily paused during scheduled maintenance periods.