Ratio Spread Risk - The Naked Leg, Margin and Broker Approval

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

A ratio spread's extra risk sits in the one option it sells beyond what it buys. In a 1x2, one short option pairs with the long option as a vertical spread with a capped loss; the second short option has nothing behind it. That uncovered option, the naked leg, is what drives the large or unlimited loss, the margin requirement and the broker approval level.

A backspread reverses this: it buys the extra option, so every short option is matched by a long option that caps its loss, and the worst case is defined. This lesson shows how to find the naked leg, its minimum margin and the permission it needs.

Where does a ratio spread's extra risk sit?

Take the 1x2 call ratio spread from this module: buy one XYZ 50 call for $2.24, sell two XYZ 55 calls for $0.60 each. Split it in two:

• A bull call spread: buy the 50 call, sell one 55 call. Cost $164, maximum loss $164, maximum profit $336.
• One naked 55 call, sold for $60. Its loss has no limit above $55.60.

Add them together and you get the ratio spread exactly: a $104 debit, a best case of +$396 and no limit on the loss above $58.96.

The same split works for every uneven spread. Count the short options and the long options of the same type and expiration. Whatever is short beyond the longs is uncovered. A 1x3 has two naked options; a 2x3 has one. A long option at a further strike, as in a backspread, does not cover a short one share for share, but it caps the pair's loss at the strike gap. A put ratio spread's naked put loses heavily but stops at zero.

This also tells you how to remove the call ratio spread's undefined risk: buy back coverage for the naked leg. Adding one long XYZ 60 call (a model price of $0.11) to the call ratio spread turns it into a 50/55/60 long call butterfly, the structure Course 3's Butterfly Spread Explained lesson covers. The cost rises to $115, and that $115 becomes the most it can lose at any price.

How much margin does a ratio spread require?

The covered part is margined as a spread, which for a debit spread usually means paying the debit in full. The naked leg is margined as an uncovered option. Under FINRA Rule 4210, the minimum for one uncovered stock option is:

• 100% of the option's current value, plus 20% of the underlying stock's value, minus any out-of-the-money amount,
• but not less than the option's value plus 10% of the stock's value for a call, or 10% of the strike value for a put.

Three things make the real number larger or less predictable:

1. House requirements. FINRA's figure is a floor. Brokers can and often do require more for uncovered options, especially around earnings or for volatile stocks.
2. It moves with the stock. As XYZ rises toward and past $55, the out-of-the-money reduction shrinks to zero and the option's value climbs, so the requirement grows. That can trigger a margin call at the worst time.
3. It needs a margin account. Uncovered writing generally cannot be done in a cash account. The cash vs. margin lesson in Course 1 covers how margin accounts work.

What options level do you need for a ratio spread?

Course 1's options trading levels lesson explains how approval works in general. Uneven spreads add one rule: the naked leg decides the level.

FINRA Rule 2360 requires firms that allow uncovered short options to set specific criteria for approving those accounts, have a Registered Options Principal approve them in writing, set minimum net equity requirements, and give the customer a special written statement on the risks of uncovered writing before the first uncovered trade.

Broker approval levels differ. In general, a trade where every short option is matched by a long option falls under spread permission, and a trade with an uncovered short option needs uncovered-writing permission, usually the highest level, with a margin account and a minimum equity the broker sets. Check your broker's current options agreement to see where each structure falls, including how it treats a put ratio spread's extra short put.

So the same two strikes can need different permissions: the backspread needs spread approval, and the ratio spread needs uncovered-writing approval.

How do traders manage the naked leg?

• Size for the stress case, not the debit. A $104 trade whose loss can run to thousands should be sized by the loss you would take after a large gap, such as the -$1,104 at $70 on the call ratio spread.
• Avoid known gaps. Earnings dates, drug trial results and merger news are when a naked call or put is most likely to jump past the break-even.
• Decide the exit first. For example, buy back the extra short option, or close the whole spread, if the stock trades through the short strike.
• Watch for early assignment. An in-the-money short call is most likely to be assigned just before an ex-dividend date. Assignment on the naked call creates a short stock position overnight.