Trading an Options Book and Stock Tape Reading

[daytrader06]

Quote from nonprophet:

dt06, exercise/assignment happens overnight and transferred shares will not “print”; consequently anything printed is not related to exercise.

AFAIK the only way to determine exercise is through Volume/OI analysis.

Thx nonprophet.

More exactly, can I say the only way to determine exercise is through overnight volume/oi analysis?

 

[nonprophet]

I think that’s correct: early exercise data are not made public.

Specifically a openinterest DE-crease that is larger than the day’s 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 (don’t 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.

 

[daytrader06]

Quote from nonprophet:

I think that’s correct: early exercise data are not made public.

Specifically a openinterest DE-crease that is larger than the day’s 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 (don’t 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.

Thx for further explaination