SPAN Margin - How Futures Option Margin Works

Reviewed by Leon Moyer - Published October 9, 2026 - Last reviewed October 9, 2026

SPAN margin is the minimum margin that futures exchanges require on a portfolio of futures and futures options, calculated by the Standard Portfolio Analysis of Risk system: it tests how much the whole portfolio would lose under a set of one-day price and volatility scenarios, and sets the requirement at the largest of those losses.

Margin means something different in futures than in a stock account. The National Futures Association (NFA) defines futures margin as "a good faith deposit or performance bond" (NFA Margins Handbook). You are not borrowing to buy anything. You are posting collateral so that, if your positions lose money, the losses can be paid.

Do futures option buyers and sellers both post margin?

No. The two sides are treated very differently.

• Buyers pay the premium. On U.S. futures exchanges such as CME Group, a buyer generally pays the full premium when the trade is made, and that is the end of their exposure. NFA's handbook notes that "a long option position can never be at risk for more than its premium". The industry's standard risk disclosure (FIA's, posted on the CFTC's website) adds that some exchanges in some jurisdictions let buyers defer the premium, in which case margin calls up to the premium are possible (FIA Combined Disclosure Statement).
• Sellers post margin. A seller receives the premium but takes on a risk that has no fixed limit. The same disclosure warns that a seller "may sustain a loss well in excess of" the premium received and "will be liable for additional margin to maintain the position if the market moves unfavorably".

So for a futures option buyer, the maximum loss is the premium paid.

How is SPAN margin calculated?

SPAN looks at a whole account rather than one position at a time. NFA's handbook describes the method; in three steps, it works like this.

1. Scan ranges. For each product, the exchange sets a price scan range (the move it considers reasonably likely in one day) and a volatility scan range (the likely change in implied volatility, which matters for options).
2. Sixteen scenarios. SPAN builds a risk array of 16 "what if" scenarios: futures unchanged, up and down one third, two thirds and the full scan range, each with volatility up and down, plus two extreme moves of which only a fraction of the loss is counted.
3. Largest loss. It values every futures and option position in each scenario, and the largest portfolio loss becomes the margin requirement, adjusted for spreads between months and related products and subject to a minimum charge for short options.

The scenario approach is why SPAN handles options sensibly. A short option can lose far more in a big move than a small one, and its value also changes with volatility. Testing both directions and both volatility shocks captures that.

The handbook is an older edition, and its numbers are illustrative. It describes the classic SPAN method. CME Group has since moved major energy and equity index products to a newer framework, SPAN 2, which models risk differently, so crude oil is no longer margined exactly this way (CME Group: SPAN 2 framework rollout). The idea is the same: margin reflects the modeled one-day risk of the whole portfolio.

How do margin calls work in a futures account?

Futures accounts settle in cash every day. The CFTC notes that customer accounts are adjusted to reflect each trading day's market value at the close (CFTC: Futures Market Basics). Gains are credited and losses are debited, so a losing position draws down your cash day by day rather than only when you close it.

When equity falls below the maintenance requirement, the broker issues a margin call. FIA's standard risk disclosure is blunt about what follows: you may be called on to deposit a substantial amount of additional funds on short notice, and if you do not, your position may be liquidated at a loss, with you liable for any deficit. Losses can exceed the money you deposited.

Two broker details matter here:

• Brokers can ask for more than SPAN. NFA's handbook notes that futures commission merchants may set higher margin requirements at their discretion.
• Requirements can change. Exchanges raise margins when markets become more volatile, and NFA notes that changes generally apply to existing positions as well as new ones.

Why does SPAN matter if you only buy options?

Because a long option can become a futures position. If you exercise, or your in-the-money option is exercised automatically at expiration, you hold futures, and futures need margin from that day. A trader who bought a $3,000 gold call without spare cash can end up with a futures position whose margin they cannot meet. The lesson Exercising Futures Options shows the cash flows.