Volatility term structure: compare expirations and event risk

Compare implied volatility across expirations to identify event exposure. Separate annualized volatility from total movement over each horizon.

By OptionsKing. Publisher and editorial methods.

Hold the underlying and strike convention constant while moving across dates. A shorter event-containing expiry can have higher annualized IV than a longer one yet a smaller total expected move. The table shows both, making the calendar's role in each contract visible.

One chain, six expiries

Nike, June 3, stock at $74.20. Earnings June 26, after the close.

Three separate things are happening in that column and they are worth separating.

1. The gentle upward slope at the front

24 at three days, 26 at seventeen. In calm markets the near term is quieter than the far term, because the near term contains only the days you can nearly see and the far term contains everything that might go wrong. Contango, if you want the futures word for it.

2. The kink

Separate event variance from ordinary variance before interpreting the jump. Under a constant 26 percent baseline and one event day, the example implies event variance of 0.41 squared times 30/365 minus 0.26 squared times 29/365: an event-day standard deviation of about 9.2 percent. This estimate depends on the chosen baseline.

26 at seventeen days, then 41 at thirty. Fifteen points, from one expiry to the next, on the same stock on the same morning.

The only difference between those two contracts is that June 26 falls inside the second one. That is the earnings print, priced.

Here is how to extract what the market thinks the print is worth. The June 20 contract carries 17 days of ordinary volatility. The July 3 contract carries 30 days, of which 29 are ordinary and one is the event. Total variance is additive over time, so the difference between the two, scaled, is the market's price on that single session. Do it on these numbers and the print is being priced at an event day worth roughly a 9.2 percent move on its own under the stated one-event-day assumption, with the remaining sessions at their normal 26.

You do not need to run that arithmetic to trade. You need to know that the 41 is one date, not a regime, and that it is why the IV rank your platform prints is misleading right now.

3. The decay back down

41, then 37, then 33, then 30. Every one of those expiries contains the June 26 print. What changes is how much else they contain. One event inside 30 days dominates the average. The same event inside 171 days is a rounding error, and the November contract settles near Nike's long-run level of about 30.

The long end averages exposure over more time, but remains a model-implied price that can include several events and changing risk premiums.

Backwardation, and what it means

The curve inverts in a crisis. Front-month goes above back-month, sometimes by a lot, because the panic is now and nobody believes it lasts a year. VIX futures did this in March 2020 and in every real dislocation before it.

For a seller, an inverted curve is the loudest signal on the screen and it says two opposite things at once. The front-month premium is spectacular. It is spectacular because the market is pricing genuine near-term chaos, and it is very often right. A short book entering that environment does not need more contracts on.

Picking an expiry off the curve

• Want the premium without the event: sell the last clean expiry. June 20 at 26 percent, expiring six days before the print. Smaller credit, no gap risk, and you get to reassess afterwards.
• Want the event premium: know you are buying a lottery ticket in reverse. July 3 at 41 percent pays roughly twice as much per day of exposure. You are being paid well for the one risk on the page that can move the stock 8 percent overnight.
• Do not sell the far-dated contract expecting the event premium. The August and November expiries also contain the print and pay almost nothing extra for it, while committing your capital for months. This is the trap: the event premium lives almost entirely in the first expiry after the date.
• Roll toward the kink, not through it. If you are already short something expiring before the print, rolling to the next expiry moves you from 26 to 41 and quietly changes what your position is. Sometimes that is the trade. It should never be an accident.

The habit worth forming

Before you sell anything, read two numbers off the chain: the nearest clean expiry and the first one containing the next event. On Nike that is 26 and 41. Those two numbers tell you the stock's ordinary volatility, the size of the event, and which expiry you are actually choosing between, and none of it can be corrupted by a spike eleven months ago.

Common questions

Sources

• OCC, Characteristics and Risks of Standardized Options

Rules and thresholds above were checked against these documents on August 4, 2026. Exchange and broker rules change. Confirm anything you are about to act on with your own broker.

Keep reading

• What happens to the kink the morning after
• How the kink corrupts a single-number IV read
• Choosing an expiry on the call side

Do the math on your own trade

• Implied volatility calculator solve for IV from a market price, and get the move it implies.
• IV rank calculator whether today is actually a high-premium day.
• Annualized return calculator turn any credit and any holding period into a yearly rate.

Every price in this article is an illustrative worked example, not a quote. Read Volatility for the rest of the series, and the disclaimer before you act on any of it. Selling options carries real risk of loss, and the loss can be far larger than the premium you collected.