OI Shift and Change Analysis in Intraday Options Trading

Open Interest (OI) analysis is one of the most critical components for intraday option traders, especially when dealing with indices like NIFTY and BANKNIFTY. OI tells you how many contracts are currently open (i.e., not yet squared off) at a particular strike price. But when used intraday, the real power comes from tracking OI changes and shifts in real-time. This gives deep insights into market participants' behavior, especially institutional traders. The concept is straightforward: if you see a significant increase in Call OI at a strike above the current market price, it usually indicates resistance – sellers are active there. Conversely, if Put OI increases at a strike below the market price, it signals support – put writers expect the price to stay above that level. But the real game changer is how these positions shift during the day. For example, let’s say in the morning session, highest OI is at 25000 CE and 24800 PE. The market trades around 24900. Now, during the day, if you see call writers moving from 25000 to 25100 (unwinding 25000 CE and adding to 25100 CE), it’s a bullish sign. It means resistance is shifting higher, and call writers are not confident in holding their position at 25000. That’s when traders look to buy call options for an intraday move. Similarly, if put writers shift support levels upward, it's confirmation of bullishness. On the bearish side, if put writers are seen exiting (OI decrease in PEs) and call writers aggressively build positions at lower strikes, it signals downside pressure. This is a good trigger to go short using put options. Monitoring intraday OI change at 5-minute or 15-minute intervals using a live OI dashboard can reveal sharp changes before price even reacts.