Open interest is the number of contracts held by traders in active positions — they're not closed or expired. For Ethanol T2 FOB Rdam Including Duty (Platts) Futures this number is 893.00. You can use it to track a prevailing market trend and adjust your own strategy: declining open interest for Ethanol T2 FOB Rdam Including Duty (Platts) Futures shows that traders are closing their positions, which means a weakening trend.