Re: What Are Open Interest Share Addition and Substraction
Open interest is the total number of options and/or futures contracts that are not closed or delivered on a particular day. Open interest is NOT the same thing as volume of options and futures trades.
On Jan 1, A buys an option, which leaves an open interest and also creates trading volume of 1
On Jan 2, C and D create trading volume of 5 and there are also 5 more options left open
On Jan 3, A takes an offsetting position and therefore open interest is reduced by 1, and trading volume is 1
On Jan 4, E simply replaces C and therefore open interest does not change, trading volume increases by 5.
Open interest, the total number of open contracts on a security, applies primarily to the futures market. It is often used to confirm trends and trend reversals for futures and options contracts.
What Open Interest Tells Us
A contract has both a buyer and a seller, so the two market players combine to make one contract. The open-interest position that is reported each day represents the increase or decrease in the number of contracts for that day, and it is shown as a positive or negative number. An increase in open interest along with an increase in price is said to confirm an upward trend. Similarly, an increase in open interest along with a decrease in price confirms a downward trend. An increase or decrease in prices while open interest remains flat or declining may indicate a possible trend reversal.