WhitmanTrading

Debit Spreads: Cheaper, With a Ceiling

A debit spread is buying one option and selling a further one of the same type to reduce the cost. The sold leg lowers the price paid and the breakeven, and in exchange it caps the maximum gain at the width between the strikes.

How it works

The underlying price swept from low to high above, and the profit and loss of a call debit spread at expiry below, with the breakeven marked. The headline on the chart reads: Buy one option and sell a further one to cut the cost.
Buy one option and sell a further one to cut the cost. Illustrative chart - not real market data.

Buy an option and sell a further one of the same type to reduce what you pay. Same expiry, different strikes, and the net cost is the debit.

The sold leg does two things at once. It reduces the price, which improves the breakeven, and it gives away everything above its strike.

The underlying swept from low to high above, with the payoff of a plain long call below. The headline on the chart reads: Cheaper than the call alone, with the upside capped.
Cheaper than the call alone, with the upside capped. Illustrative chart - not real market data.

Compared with the bare call, the difference is on the right-hand side. The call’s line keeps rising; the spread’s goes flat at the far strike.

The numbers

Long call at 100, short call at 110, net cost 3:

Maximum loss −3 — what you paid
Maximum gain +7 — the 10-point width minus the 3 paid
Breakeven 103 — the long strike plus the debit
At or above 110 full profit, and no more
At or below 100 full loss

Set that against the bare call, which on this site’s worked example costs 4 and breaks even at 104. The spread costs 3, breaks even at 103, and gives up everything above 110.

A 72-bar candlestick section of the shared price history. The headline on the chart reads: Maximum gain is the width minus what you paid.
Maximum gain is the width minus what you paid. Illustrative chart - not real market data.

The ratio here is +7 to −3, which is the reverse of the credit spread’s +3 to −7. This position wins less often and wins more when it does, and that trade-off is the entire difference between the two structures.

In practice: what it removes

The underlying swept from low to high above, with a vega curve below. The headline on the chart reads: And it is far less exposed to a volatility change.
And it is far less exposed to a volatility change. Illustrative chart - not real market data.

The most useful property is reduced volatility exposure. The bought and sold legs have opposing vega, so a general fall in expected volatility hurts one and helps the other. Much of the “right about direction, lost anyway” problem disappears here.

A flat, quiet stretch of the long price series with an extrinsic-value curve decaying below it. The headline on the chart reads: The sold leg pays for part of the decay.
The sold leg pays for part of the decay. Illustrative chart - not real market data.

Decay is reduced for the same reason. You pay theta on the long leg and collect it on the short one, so the position bleeds more slowly than a single option — which makes it more tolerant of being early.

The underlying swept from low to high above, with a delta curve below. The headline on the chart reads: It is a directional position with both ends known.
It is a directional position with both ends known. Illustrative chart - not real market data.

What remains is a directional position with both ends known before entry. That is a genuinely different instrument from a bare option, and the certainty is worth something.

A flat but volatile stretch of the long price series. The headline on the chart reads: The best case is a move to the far strike and no further.
The best case is a move to the far strike and no further. Illustrative chart - not real market data.

The ideal outcome is a move that reaches the far strike and stops. Anything beyond it belongs to whoever bought the option you sold, which is the cost of the discount.

What a debit spread is not

It is not a cheaper call. It is a different payoff with a ceiling, and the saving is the price of the ceiling rather than a discount.

It is not immune to time. Decay is reduced, not removed, and a spread that never gets near the far strike still expires worthless.

It is not a small position because the debit is small. The maximum loss is the debit, which is genuinely capped — but sizing by cost rather than by exposure still puts too many contracts on.

And it is not a way to avoid being wrong about direction. It is directional. Everything about it depends on the move happening, and it simply removes two of the three ways to lose while being right.

When it fails

A declining stretch of the long price series. The headline on the chart reads: And a move the wrong way loses the whole debit.
And a move the wrong way loses the whole debit. Illustrative chart - not real market data.

A move the wrong way loses the full debit, exactly as a bare option would, and the reduced cost is the only consolation.

A sideways, range-bound candlestick series. The headline on the chart reads: A flat market still loses, just more slowly.
A flat market still loses, just more slowly. Illustrative chart - not real market data.

A flat market still loses. More slowly than a single option, and it arrives at the same place by expiry.

A candlestick chart of the site's shared price history, annotated with the round-trip cost. The headline on the chart reads: Two legs of spread plus 2% a bar on the underlying.
Two legs of spread plus 2% a bar on the underlying. Illustrative chart - not real market data.

Four option spreads are paid across the position’s life — two to open, two to close — against a maximum gain of 7. On a narrow spread those costs are a substantial fraction of the best case.

The third failure is a huge move. Being capped at the far strike during the one move that would have paid for a year of attempts is the specific regret this structure creates, and it is the price that was agreed at entry.

A fourth is choosing strikes too far apart. A wide spread costs more, behaves more like the bare option, and gives up less — which means it also gives up most of the reasons for using a spread.

And a fifth is closing only one leg. Taking off the short side of a working spread converts a defined-risk position into an open-ended one, usually at the moment that feels safest.

A sixth is waiting for the full width. A spread reaching its maximum requires price to sit above the far strike at expiry, and holding for the last point or two of a 7-point gain means carrying the position through the period where gamma is largest for the smallest remaining reward.

The structure earns its place by removing two of the three ways to lose. A bare option can lose on direction, on time, or on volatility. A debit spread substantially reduces the second and the third, which leaves direction — the thing you actually formed a view about. Paying for that with the tail above the far strike is a reasonable trade whenever the view is about a move rather than about a melt-up, and it is a poor one whenever the whole reason for the trade was the tail.

The original data

1 of the 24,971 videos measured for this site covers debit spreads, at a median of 8,884 views — the smallest supply of any options structure here, despite it being the most straightforward way to express a directional view without carrying full volatility exposure.

A candlestick chart of the site's shared price history, cut short at the decision bar. The headline on the chart reads: Halfway to the far strike with a week left. Hold?
Halfway to the far strike with a week left. Hold? Illustrative chart - not real market data.

The −3 and +7 were computed from the stated contract — long 100, short 110, net 3 — and the breakeven at 103 follows. Drawing both this and the equivalent credit spread side by side is the single clearest way to see what each structure is actually buying.

Credit spreads invert this ratio and the comparison teaches both. Call options is the single-leg version this is built from. And vega is the exposure this structure exists to reduce.

What I actually do

I moved to debit spreads for directional trades after working out how much of my single-option losses were volatility rather than direction. Giving up the tail was worth it to stop losing on positions where I had actually been right.

— Michael Whitman

This page is educational, not financial advice. Test every idea on your own charts before risking money.