Ask five options traders when a contract expires and you’ll likely get three different answers, and all three will sound confident. Some will say 4:00 PM. Others will say 4:15 PM. A few old-timers will insist it’s actually Saturday. All of them are half right, because “expiration” in options trading isn’t one moment. It’s a sequence of cutoffs spread across nearly ninety minutes, and mixing them up is exactly how traders get blindsided by assignment they didn’t see coming.

Last Trading Day Is Not the Same as Expiration Date

For decades, a standard listed equity option’s official expiration date was the Saturday following the third Friday of the month, a paper-processing buffer left over from an era when contracts were settled by hand. The Options Clearing Corporation retired that quirk for contracts expiring after February 1, 2015, moving the legal expiration date onto the Friday itself. Anyone still reading an older guide that says options expire on a Saturday is looking at a fossil of that old system, not current practice.

Even now, the contract’s formal “expiration time” is 11:59 PM ET on that Friday. That figure rarely matters to a trader in practice, since trading, exercise decisions, and automatic exercise all happen hours earlier in the afternoon, but it’s the actual legal moment the contract stops existing, and it’s worth knowing that number if you ever need to read an options exchange rulebook literally.

What matters day to day is the last trading day, the final session where the contract can actually be bought or sold. For standard monthly contracts, that’s the third Friday of the month, or the Thursday before it if Friday falls on a market holiday. That’s the date printed on your platform’s option chain, and it’s the one that counts for anything you’re actively trading.

Why 4:00 PM for Some Contracts and 4:15 PM for Others

This is where the 4:00 vs 4:15 confusion actually comes from, and it has a clean explanation once you separate the two product types. Trading in standard equity and ETF options ends at 4:00 PM ET, the same moment the underlying stock market closes. Broad-based index options, SPX and NDX among them, trade on a slightly longer clock and stop at 4:15 PM ET, fifteen minutes after the equity market shuts. Anyone comparing notes between a stock options trader and an index options trader, without realizing they’re talking about two different product classes, will walk away thinking one of them has the wrong time. Neither does.

The 90-Minute Gap Nobody Tells You About

Trading stops at 4:00 PM, but the decision isn’t final yet. Option holders have until 5:30 PM ET, ninety minutes later, to submit exercise or do-not-exercise instructions, a deadline set by the Options Clearing Corporation. Most brokers impose their own earlier cutoff for customers, commonly around 4:30 PM ET, so an investor’s real deadline is usually whatever their brokerage sets, not the OCC’s outer limit.

Any contract that closes even a penny in the money at 4:00 PM is automatically exercised unless the holder actively opts out before their broker’s cutoff. That automatic step exists to protect holders from losing value to a missed deadline, but it also means the decision is made on the 4:00 PM closing price, not on anything that happens afterward.

The market closes once. The option doesn’t finish deciding what it’s worth until ninety minutes later. worldtimedata

Where This Gap Actually Bites: Pin Risk

The underlying stock keeps trading in the after-hours session until 8:00 PM ET, well past both the 4:00 PM options close and the 4:30 to 5:30 PM exercise window. A stock that closes just below a strike at 4:00 PM, and then drifts above it on an earnings headline at 4:20, can leave a short option writer unable to hedge a position they don’t yet know they’ll be assigned on. Traders call this pin risk. It isn’t a formal regulatory term, but the exposure is real, and it’s a direct consequence of these two clocks, the option’s and the stock’s, not running on the same schedule.

The Other Mix-Up: AM-Settled vs PM-Settled

Most equity, ETF, and weekly index options are PM-settled, meaning the final settlement value comes from the closing price on the last trading day itself. But some older-style monthly index contracts are AM-settled, which means their last trading day is actually the day before the stated expiration date, and the final settlement value is calculated from the opening prices of the index’s component stocks the following morning. A trader who assumes every contract behaves like a PM-settled one can end up holding a position through an overnight move they thought they’d already avoided by exiting on the “last day.”

Why This Cluster of Deadlines Matters Four Times a Year Especially

All of this gets amplified on the quarterly dates when stock options, index options, and futures contracts expire simultaneously, a convergence known as triple witching. Volume and volatility both spike in the final hour of trading precisely because so many of these overlapping deadlines land on the same afternoon, making the 4:00 to 4:15 PM window on those days one of the busiest stretches on the entire calendar, well outside the normal rhythm covered in market hours.

What to Actually Track

If you trade options regularly, three numbers matter more than any single “expiration time”: the 4:00 or 4:15 PM cutoff for your specific product type, your own broker’s exercise deadline, which is almost always earlier than the OCC’s, and whether the contract is AM-settled or PM-settled if it’s an index product. Get those three right and the rest of the confusion, Friday versus Saturday, 4:00 versus 4:15, disappears on its own.