Striking Price Interval

Striking price interval is the standard gap between one available strike price and the next, for options listed on a given underlying stock, ETF, or index. Options don't trade at every possible price; exchanges list them in preset steps, and the striking price interval is the size of that step.

For example, if a stock's options are listed in intervals of 5 points, you might see strikes at 95, 100, 105, 110, and so on, with nothing in between. The interval usually scales with the underlying's share price: cheaper stocks tend to get tighter intervals so traders have meaningful choices near the current price, while more expensive stocks get wider intervals, since a 1-point gap on a $500 stock would be a much smaller percentage move than a 1-point gap on a $20 stock.

The nuance that trips people up is that the interval is not fixed by a single universal rule you can memorize once and rely on forever. Exchanges set and periodically adjust these intervals, and they can also list additional "intermediate" strikes closer to the current stock price for actively traded names, even if that breaks the normal step pattern further out. So the actual available strikes for any given stock should be checked in the option chain itself rather than assumed from a general guideline.

It's also worth separating this from strike price itself: the strike price is the fixed price at which an option can be exercised, while the interval is simply the spacing between one strike and its neighbors on the chain.