Open Interest is the total number of futures contracts that have not yet been offset by an opposite futures transaction. It is a clear indication of the contract's growing liquidity and strength and also shows that users, in addition to day-trading the mini-Dow, are using the contract for longer term positioning and for risk management.
The CBOT mini-sized Dow was launched in April 2002. It is 100% electronic and trades almost around the clock. The contract offers low margins which allows users to have greater leverage in the marketplace. It continues to be one of the fastest growing products at the CBOT, with average daily volume increasing over 19% per month.