Chapter 04 · Section 4.1

Call Day 2

Here are all the transactions of day 2. (We keep the records of the first day because they still have an effect). 

Day 1                        Day 2
Al  buys  5 Sep 35 calls.    Al  sells 8 Sep 35 calls.
Sam sells 2 Sep 35 calls.    Sam sells 1 Sep 35 calls.
Tim sells 3 Sep 35 calls.    Tim buys  9 Sep 35 calls.


                             ABC Stock Options
                    CALL                              PUT
               Day 1    Day 2                    Day 1    Day 2 
Open interest : 5        ...      Open interest : 0        ...
Trading volume: 5        ...      Trading volume: 0        ...
What are the call open interest and trading volume figures for day 2? Calculate the net position of each of the three traders. Add up all the resulting long positions. They should be the same as the total of the resulting short positions. And that is open interest. As for trading volume, add up the number of contracts that have been sold (or bought) during day.