OI Change is the daily flow signal. Where it's positive, fresh positioning; where it's negative, unwinding.
OI Change = today's change in open interest at a strike. Positive = positions opened. Negative = positions closed.
OI Change is the daily flow signal that pairs with cumulative OI. Together they tell you both where positioning lives AND what's shifting today.
Large positive OI change at call strikes: fresh call writing or buying. Combined with price falling = bearish call writing. With price rising = call buying.
Large negative OI change at call strikes: call writers covering. Often a sign that the level isn't being defended; resistance could break.
Same logic for puts. Big positive at put strikes = put writing (bullish, defending the level) or put buying (bearish, fearing the level).
On expiry day, OI Change is mostly negative (positions closing into settlement).
Earlier in the week, large positive OI change clusters tell you where institutions are positioning for the rest of the week.
Strota's chain highlights the top 5 OI change strikes — easy to spot the day's positioning shifts.
From price action that day. If the call price rose AND OI increased, buyers drove it. If call price fell AND OI increased, sellers (writers) drove it. The price-OI cross is the signal.
Above 20% of the strike's prior OI is significant. Above 50% is unusual and worth investigating. NSE publishes daily OI change in the F&O bhavcopy.
Monthly OI changes are stickier (less intraday noise). Weekly OI Change is more reactive and shorter-lived.