These filter stocks based on the number of options traded so far today.  You can filter stocks based on the exact number of contracts they’ve traded today.  Or you can compare the number of contracts traded today to the number of contracts the same stock usually trades in an entire day.

For example, let’s say you are looking for stocks with unusually high options volume.  You set the minimum value for this filter to 200%.  Then you will only see stocks which have already traded twice as many options today as they trade on a normal day.

For another strategy, maybe you don’t care about the historical baseline.  If you are looking for a stock with decent liquidity, then you would use the other form of this filter.  You might set the minimum value to 5,000 contracts.  This would only list stocks which had traded at least 5,000 contracts so far today.