You basically use the paradigm for determining open interest that : A) If price moved up and OI increased, long buildup. B) If price fell and OI increased, short buildup. C) If price moved up and OI decreased, short unwinding, and D) If price fell and OI decreased, long unwinding. But if you look at a single transaction, the buyer and seller could have independent positions which could be closing or opening. So we get different cases like: 1) Both seller and buyer opening positions: Here the OI increases by 2. There can be said to be long buildup and short buildup. 2) One opening position, other closing position: Here the OI does not change at all. 3) Both closing positions: Here the OI decreases by 2. Again there is both short unwinding and long unwinding. How do you correlate this? I don't understand how you come to the conclusions that you show everyday...