IV crush is the sharp fall in implied volatility, and with it in option premiums, once an awaited event is out of the way. Before a Union Budget, a central bank decision, an election count or a company’s results, nobody knows the outcome, so options are priced for a big move in either direction. As soon as the news is known, that uncertainty disappears from the price, often within minutes of the open, even if the index hardly moves. That is why an option buyer can be right about the direction and still lose money. This guide explains what IV crush is, how much premium it can take, two real examples from 2026, and how to see it building before it happens.
What IV crush means
Every option price has two parts. Intrinsic value is what the option would be worth if it expired right now. Time value is everything above that: the price of the chance that the index moves further before expiry. How much the market charges for that chance is summed up in one number, implied volatility, the movement per year that the option price implies. Higher implied volatility means more time value and a dearer option.
Before a known event, implied volatility rises. Buyers want protection or a lottery ticket on the outcome, and writers want to be paid more for carrying the risk of a jump. After the event, the jump has either happened or not, and the extra charge for it is no longer needed. Implied volatility falls back toward normal, and the time value of every option shrinks with it. That fall is the IV crush.
How much an IV crush costs
The sensitivity of an option’s price to implied volatility is called vega: how many rupees the premium moves for a one-point change in implied volatility. For an at-the-money NIFTY option with a week to expiry, vega is roughly 12, so every point of implied volatility that drains away takes about ₹12 off each call and each put, before the index has moved at all.
Scale that up with a rough rule: an at-the-money straddle, a call and a put at the same strike, costs about 0.8 × index level × implied volatility × the square root of the time left in years. Say NIFTY is at 22,650 with a week to expiry. Priced at 18 percent volatility before an event, the straddle costs about 450 points. If the event passes, volatility settles at 13 percent and the index is exactly where it was, the same straddle a day later is worth about 300. A third of its price is gone, and the index has not moved. Anyone who bought that straddle needed the event to move NIFTY by more than the premium they paid just to break even; anyone who sold it was paid for the risk that it would.
Where IV crush happens in India
- The Union Budget. Index options price a large move into budget day, and the premium drains in the sessions after.
- Monetary policy decisions. The central bank’s rate announcements are scheduled, and implied volatility often rises into them.
- Election results. Counting days carry some of the largest event premiums of all.
- Company results. In stock options the same pattern repeats every quarter: implied volatility climbs into the announcement and drops once the numbers are out, often by far more than on an index.
- Global events. Overseas rate decisions land outside Indian market hours, so their effect arrives at the next open.
Two real examples from 2026
The Union Budget was presented on Sunday 1 February 2026, and the exchanges held a special trading session for it. NIFTY fell 1.96 percent that day, and India VIX, the exchange’s measure of the volatility priced into NIFTY options, closed at 15.10, up from 13.63 on the Friday before. It then drained: 13.87 on Monday, 12.89 on Tuesday and 11.94 by Friday 6 February, about 21 percent lower than on budget day, while the index recovered. The event had been priced, delivered and then removed from option prices within a week.
The second example is sharper. India VIX closed above 22 on every session from 19 March to 7 April 2026 and peaked at 27.89 on 30 March. On 8 April NIFTY opened more than 3 percent higher and closed up 3.78 percent, and India VIX fell from 24.70 to 19.70 in that one session, a drop of about 20 percent. Put buyers lost twice that day, on the direction and on the volatility. Call buyers made money on the direction but gave some of it back to the falling volatility. When a fear eases, implied volatility can collapse even while the index jumps. The India VIX guide explains what the index measures.
Why buyers lose even when they are right
An option bought before an event is a bet on two things at once: that the index moves the right way, and that it moves by more than the volatility already in the price. The second part is the one people forget. Suppose a stock’s call options are priced at 45 percent implied volatility before results, and the stock rises 2 percent on the day. If implied volatility drops to 30 percent after the numbers, the fall in time value can be larger than the gain from the move, and the call ends the day lower. The direction was right; the size was not enough to pay for the volatility that was bought.
The test before any event trade is simple: what move is the market already pricing? The at-the-money straddle answers that directly, which is why the expected move guide and the straddle premium chart are the places to start.
How writers see an IV crush, and the risk they take
Option writers collect the premium that the event inflated, and an IV crush is the moment that premium turns into their gain. It is not free money. Writers carry the risk that the event delivers a bigger move than was priced, and a gap through their strikes can cost several times the premium they received. The volatility risk premium, implied minus realised volatility, measures how much writers have been paid on average for that risk, and it goes negative after a shock, when the movement delivered beats the movement priced. In the budget week above it did exactly that: by 3 February realised volatility had risen above India VIX.
How to see an IV crush coming
- IV rank is high. When at-the-money implied volatility sits near the top of its own range, options are expensive against their history, and an event is a common reason.
- The term structure bends. If the nearest expiry, the one that covers the event, is priced above the next one, the market is charging specifically for the event. After it passes, that front expiry usually falls back into line.
- Both tails are bid. A rising 25-delta butterfly, BF25, means puts and calls away from the money are both getting dearer: the market is pricing a big move either way.
- The straddle is dearer than usual. An expected move well above the recent norm for the same number of days left is another sign that an event premium is in the price.
The IV term structure and skew guide explains the term structure and the 25-delta measures in detail, and the implied volatility guide covers the basics.
A worked reading
Suppose that a week before an event, IV rank for NIFTY reads 85, the nearest expiry’s implied volatility is two points above the next one, BF25 has been rising for three sessions and the at-the-money straddle prices a move well above its recent range. All four point the same way: a large event premium is in the price, and it will most likely drain once the news is out. A buyer of that straddle needs a move bigger than the one being priced; a writer is being paid well but takes the gap risk. The reading says how much the event is costing, not which way it will go.
Where to read IV crush risk in OIData
- The Volatility page shows India VIX with its percentiles, realised volatility and the risk premium, then IV rank and percentile, the IV surface, the term structure with the forward volatility between the two nearest expiries, the 25-delta skew with BF25, and the implied distribution.
- Dealer Positioning has an IV shock slider that re-prices the gamma profile for an IV crush or spike before an event, without waiting for the market to do it.
- Straddles & Strangles charts the combined premium through the session, so the drain after an event is visible minute by minute.
- The Option Chain shows implied volatility for every strike, and its IV Skew card gives the at-the-money IV with its rank and percentile.
IV crush FAQ
What is IV crush? The fall in implied volatility, and so in option premiums, after an event that the market was waiting for has happened.
When does IV crush happen? Usually at the first trade after the news: at the open after a budget or results announced outside market hours, or within minutes of a scheduled announcement during the session.
Can I lose money buying options even if I am right about the direction? Yes. If the move is smaller than the one the option price assumed, the fall in implied volatility can outweigh the gain from the move.
How do I know if implied volatility is high before an event? Check IV rank and percentile, whether the nearest expiry is priced above the next one, and how the at-the-money straddle compares with its recent range.
Does India VIX always fall after an event? Usually, once the uncertainty is resolved, but not always. If the event itself brings a shock, India VIX can rise further first, as it did on budget day 2026.
Takeaways
- IV crush is the drop in implied volatility once an awaited event is known; it shrinks the time value of every option.
- Vega measures the cost: about ₹12 per point for an at-the-money NIFTY option a week out.
- In 2026, India VIX fell about 21 percent in the week after the budget, and 20 percent in one session on 8 April.
- An option bought before an event needs a move bigger than the one already priced, not only the right direction.
- IV rank, the term structure, BF25 and the straddle price show how big the event premium is before it drains.