Thx nonprophet. More exactly, can I say the only way to determine exercise is through overnight volume/oi analysis?
I think thatâs correct: early exercise data are not made public. Specifically a openinterest DE-crease that is larger than the dayâs volume can only be explained by early exercise, except in case of contract adjustments (like splits where the number of contracts changes) and bad data (donât underestimate bad data, straight from the options exchange!). If there were no adjustments made then one additional check is to see if these options were sensible early exercise candidates in the first place. Pls beware you can only analyze this for one series at a time: you cannot compare total options volume to total OI and draw conclusions from there.