Options Settlement: AM vs PM
The Basics: What Settlement Means in Options
Settlement in options trading refers to the actual delivery of shares (or cash for index options) and payment after exercise or expiration. Unlike stock trades where settlement happens T+1 (one business day after trade), options settlement happens on expiration itself—but the timing varies significantly depending on the option type.
Most equity options settle in the afternoon (PM settlement) based on the market close price. Some index options settle in the morning (AM settlement) based on the opening price. This distinction is critical because it determines overnight risk and when you'll know your final position.
PM Settlement: Most Equity Options
The vast majority of equity options—options on individual stocks, broad ETFs like SPY, QQQ, IWM—use PM settlement (afternoon settlement). This means the settlement value is calculated based on the closing price of the underlying asset at 4:00 PM ET on expiration Friday (or whatever the final trading day is).
How PM Settlement Works:
- Expiration Friday: Last trading day at 4:00 PM ET close
- Expiration Friday night: OCC processes assignments based on closing prices
- Expiration Saturday: Assignment and exercise happen at settlement prices
- Settlement Monday: Shares and cash appear in your account (T+1 from expiration)
For PM-settled options, you don't face overnight risk on expiration day. The settlement value is locked in at 4:00 PM Friday. Over the weekend, even if futures trade or international markets move, your settlement value doesn't change. You know exactly what you're getting Monday morning.
PM settlement is preferred by many traders because it eliminates overnight gap risk on expiration day. You control the exact settlement value because it's based on the market close you can see.
AM Settlement: Index Options Like SPX
Some index options, particularly broad-based indices like SPX (S&P 500) and certain other indexes, use AM settlement. This means the settlement value is calculated based on the opening price (or special opening quotation) at the market open on expiration day.
How AM Settlement Works:
- Expiration Thursday: Last trading day at 4:00 PM ET close
- Expiration Friday: Market opens at 9:30 AM ET; special opening quotes are collected
- Expiration Friday ~8:15 AM ET: Settlement price is calculated based on special opening quotation
- Expiration Saturday: Assignment and exercise happen at settlement prices
- Settlement Sunday: Shares and cash appear in your account (T+1 from expiration)
The critical difference: you don't know the settlement price until after the market opens on Friday. If you hold AM-settled options through expiration, you face overnight risk—the index could gap up or down from Thursday close to Friday open, changing your settlement value.
Why AM Settlement Creates Overnight Risk
Overnight risk is real for AM-settled options. Between Thursday close and Friday open, significant events can occur:
- Overnight news: Economic announcements, earnings surprises, geopolitical events
- Futures trading: S&P 500 futures trade nearly 24 hours; they can gap significantly from previous close
- International markets: European and Asian markets trade Thursday night and Friday morning (before U.S. open)
- Fed announcements: Sometimes released early morning or before market open
For example, if SPX closed at 4,500 on Thursday, and overnight news triggers a 2% gap down, SPX might open at 4,410 Friday. If you're long a 4,500 call, your settlement value just dropped $9,000 (100 × $90) overnight. You had no ability to control this.
This is why experienced traders often close AM-settled options before the Thursday close rather than hold overnight.
Settlement Price Calculation
The settlement price is typically straightforward for individual stock options: it's the closing price on the last trading day. For SPX and other index options, it's the special opening quotation (SOQ)—a calculation based on opening trades of all 500 stocks in the index.
The SOQ is calculated starting at 8:15 AM ET on expiration day and published by the OCC before the market is fully open. This gives traders a chance to see their settlement value quickly, but they still can't trade if they don't like the outcome (the market has already "opened" at 9:30 AM).
Physical Delivery vs. Cash Settlement
Equity options (calls and puts on stocks) result in physical delivery: actual shares are delivered or bought when exercised. When you exercise a long call, you receive 100 shares. When a short call is assigned, you deliver 100 shares.
Index options, by contrast, are cash-settled. When you exercise a long SPX call that's in-the-money, you don't receive "100 shares of the S&P 500" (which doesn't exist). Instead, you receive cash equal to the intrinsic value at settlement.
This has important implications:
- Equity options: Require enough buying power for shares if assigned; settlement involves actual stock movement
- Index options: Cash only; no stock delivery; simpler settlement but overnight risk for AM-settled indices
European Exercise: Only at Expiration
As mentioned earlier, European-style options can only be exercised at expiration, not before. This actually simplifies settlement in some ways—there's no risk of surprise early assignment, and settlement happens exactly at expiration with no surprises before that.
However, European options still have AM vs PM settlement types. SPX is European style AND AM-settled, creating a scenario where you face overnight risk but can't trade out of it early (because the option can't be exercised before Friday).
This is why many traders consider European AM-settled options more risky than American PM-settled options: the overnight gap risk without the flexibility of early exercise.
The VIX Settlement Process (Special Case)
VIX options (volatility index options) have their own unique settlement process. They're cash-settled index options, but with special characteristics.
VIX options use a special "VIX settlement value" calculated from the opening bids and asks of SPX options on expiration Friday morning. This is different from the standard SOQ and makes VIX options particularly complex to understand.
Key points about VIX settlement:
- Settlement is AM based on a special calculation using SPX option skew
- The calculation happens around 8:15 AM ET on expiration Friday
- VIX options can be very volatile overnight if SPX opens with large gaps
- Most traders close VIX options before Thursday close to avoid overnight risk
Expiration Week Calendar and Last Trading Day Rules
For most U.S. equity options, the last trading day is the third Friday of each month. However, special rules apply:
| Situation | Last Trading Day | Settlement Day |
|---|---|---|
| Normal 3rd Friday (most equity options) | 3rd Friday at 4:00 PM | Saturday (PM settlement) |
| Index options (SPX) | 3rd Friday at 4:00 PM | Friday after market open (AM settlement) |
| Holiday interruption | Business day before holiday | Adjusted based on holiday schedule |
| Weekly options | Every Friday at 4:00 PM | Saturday (PM settlement) |
Monthly vs. Weekly Expiration Differences
Most options markets have monthly expirations (3rd Friday of each month) and weekly expirations (every Friday). Weekly options have several characteristics:
- Faster time decay: All time value is lost in one week if OTM
- Higher gamma: Price sensitivity increases dramatically as expiration approaches (5 days vs. 30 days)
- Tighter spreads: Popular weeklies have tighter bid-ask spreads due to higher volume
- More expiration events: You face expiration management every Friday instead of once a month
- Better for hedging short-term: Weekly options are ideal for protecting positions over a week
Weekly options use the same settlement timing as monthly options: PM settlement for equity options, settlement on Saturday with accounts updated Monday.
Real-World Settlement Scenarios
Scenario 1: SPX Call at Expiration with Gap Down
You're long 5 SPX calls with a $4,500 strike. Thursday close: SPX is at $4,510 (your calls are worth $1,000 per contract, $5,000 total).
Thursday night: Weak manufacturing data is released. SPX futures gap down 1%.
Friday open: SPX special opening quotation is calculated at $4,460 (a $50 gap down).
Your calls are now worth $4,460 - $4,500 = -$40... wait, they're out of the money. They expire worthless. You lose the entire $5,000 overnight with zero ability to control it. This is AM settlement overnight risk.
Scenario 2: Apple Call at Expiration (PM Settlement)
You're long 3 Apple calls with a $175 strike. Friday at 3:30 PM: Apple is at $180 (your calls are worth $500 per contract, $1,500 total).
You decide to hold. Friday 4:00 PM close: Apple closes at $180.50. Your calls are exercised automatically Saturday at $180.50 - $175 = $5.50 per share, or $550 per contract profit.
Monday morning: 300 shares of Apple appear in your account at your execution price of $175, and you have captured the $1,650 profit ($5.50 × 300). You then sell the shares if you want, knowing exactly what you got.
The key difference: PM settlement at the close lets you control the final outcome.
Scenario 3: SPY Put Spread at Expiration
You sold a put spread: short 10 puts at $450 strike, long 10 puts at $445 strike (PM-settled). Friday at 3:45 PM: SPY is at $451 (your spread is worth the maximum profit).
SPY closes at $451.20. Both your short and long puts expire worthless. You keep the entire spread credit. Monday morning: the credit appears in your account. Clean trade, no surprises.
The PM settlement meant the outcome was locked in at 4:00 PM Friday, and there were no overnight surprises.
Planning for Settlement
For PM-Settled Options (Most Equity Options):
- You have until 4:00 PM Friday to decide whether to close, exercise, or let expire
- Settlement value is locked in at market close
- Settlement occurs Saturday with accounts updated Monday
- Plan for Monday morning: will you have shares to sell? Cash to invest? Margin calls to cover?
For AM-Settled Options (SPX, Some Indices):
- Close positions before Thursday 4:00 PM close to avoid overnight risk
- If you hold overnight, expect potential large gaps Friday open
- Settlement value is determined by Friday opening prices, not Thursday close
- Settlement occurs Friday after open (weekend settled in some cases)
Conclusion
Settlement type is often overlooked by new traders but is critical to understanding options risk. PM settlement (equity options) is straightforward and predictable. AM settlement (index options) creates overnight gap risk that experienced traders actively avoid. Understanding the differences between physical and cash settlement, knowing when settlement prices are locked in, and planning for the mechanics of how shares and cash move into your account will make you a more confident options trader.