you are viewing a single comment's thread.
Isn't it possible to tell from the open interest numbers whether it was a buy to open or sell to close? Anyone keep track of the open interest?
It is true that a
"TO OPEN" transaction increases the OPEN INTEREST
"TO CLOSE" transaction decreases the OPEN INTEREST
The problem is that the
"TO OPEN" can be a SELL or a BUY instigated transaction.
"TO CLOSE" can be a SELL or a BUY instigated transaction.
The next day OPEN INTEREST is
todays OPEN INTEREST + all TO OPEN transactions - all TO CLOSE transactions.
There could be a mix of open and close transactions.
Today I could SELL TO OPEN some call options early in the day and then BUY TO CLOSE near the end of the trading session for a profit. I think there are people who do same day buy/sell of options.
Even the option sites make simplifying assumptions that are guaranteed. I think they can see if the transaction takes place at the BID or the ASK and which way the stock and volatility is going.