Hacker News Reader

Comment by SamReidHughes | Hacker News Reader

If you make a mid-day order on an exchange you would be able to trace the transaction to a specific buyer and seller, because a specific counterparty got matched with your order. But if you exercise an option, or buy at the opening or closing auction, the shares are naturally commingled together.

View on HN

I thought options were also explicitly assigned for fulfillment (randomly among those matching) so you could match it to specific shares if you wanted.

Brokers get told how many assignments they need to make and then they hand them out randomly to their customers. My impression was that the number of exercises gets added up by the OCC and there is no chain of permutations recorded tying an individual exercise to an assignment from one broker's customers to another.

My belief here is based solely on having read some documents about the assignment process and having seen no reference to such record-keeping.

Ah, I didn't realize the OCC commingled everyone's orders like that. Somehow I thought they were acting as an insurer on a bunch of 1 on 1 transactions. But I'll admit my understanding is probably incorrect in light of your specific knowledge.

I want to reiterate, I don't have specific knowledge, I am a retail end-user drawing conclusions from reading things like these assignment process documents:

https://www.theocc.com/getmedia/0cdda3c2-ab81-450f-b8b8-7ce8... https://gdcdyn.interactivebrokers.com/Universal/servlet/Regi...

Reply on news.ycombinator.com