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Key Takeaways
- A debit spread buys one option and sells another for less premium, so cash leaves the account when the position opens.
- For a vertical debit spread, maximum loss is the debit paid and maximum profit is the strike width minus that debit.
- Bull call spreads express an upside target, while bear put spreads express a downside target.
- The short leg lowers cost and break-even distance, but it also caps the payoff once the underlying moves through its strike.
- Both legs should be entered and exited as one spread order so execution quality and defined risk stay intact.
What is a debit spread?
A debit spread is an options strategy that buys one option and sells another of the same type and expiration at a different strike, paying more premium than it collects. The debit is the maximum loss, and the short option caps the profit at the strike width minus the debit. The two common forms are the bull call spread and the bear put spread.
A vertical debit spread uses matching underlying, option type, expiration, deliverable, and quantity, with different strikes. The bull call version buys the lower-strike call and sells the higher-strike call. The bear put version buys the higher-strike put and sells the lower-strike put. The short option funds part of the purchase and sets the top of the complete expiration payoff.
How to calculate debit spread profit, loss, and breakeven
For a vertical debit spread, maximum expiration loss equals the opening debit. Maximum expiration profit equals strike width minus debit, multiplied by the contract multiplier and quantity.
A bull call spread breaks even at the long call strike plus the debit per share. A bear put spread breaks even at the long put strike minus the debit per share.
The example buys the 100 call for $4.20 and sells the 110 call for $1.70. One standard spread costs $250, has $750 maximum expiration profit, and breaks even at $102.50.
At $98, the expiration loss is $250. At $106, the spread is worth $600 and earns $350. At $110 and every higher expiration price, the package is worth its full $1,000 strike width and earns $750.
Worked Example
XYZ trades at $100. A trader buys one 100 call for $4.20 and sells one 110 call with the same expiration for $1.70. The standard equity contract multiplier is 100 shares.
- Net debit = ($4.20 − $1.70) × 100 = $250, which is the maximum loss.
- Maximum profit = ($10.00 width − $2.50 debit) × 100 = $750.
- Break-even price = $100 long strike + $2.50 debit = $102.50.
If XYZ closes at $98, both calls expire worthless and the trader loses the $250 debit. At $106 the long call is worth $6.00 and the short call expires worthless, so the spread is worth $600 for a $350 profit. At $110 or any higher price the spread reaches its full $10.00 value and profit stops at $750, because gains on the long call are offset by losses on the short call above 110.
Payoff at expiration
Illustrative figures from this page's example, priced by the InsiderFinance options profit calculator. Probability assumes 25% volatility, a 4% rate and 45 days to expiration.
- Max Profit
- $750.00
- Max Loss
- -$250.00
- Break-Even
- $102.50
Interactive payoff loads as you reach it
Load this setup on live SPY options. Move the strikes and scrub to any date.
Build This StrategyHow to choose debit spread strikes
Select the short strike around the destination you want to evaluate. Compare long strikes by entry debit, breakeven, maximum profit, and dollar loss limit. Use gamma exposure, price structure, and expected move to build the price scenarios.
The example’s short call reduces the entry cost from $420 for the long call alone to $250. It also lowers expiration breakeven from $104.20 to $102.50. Compare those figures with the payoff above the $110 short strike. The options profit calculator compares the cost, breakeven, complete expiration curve, and current exposure before the position is sized.
Debit spread P&L before expiration
Current P&L equals the spread’s closing value minus its entry debit. Both legs have price exposure before the stock reaches their strikes. Calculate their combined delta, theta, and vega to inspect the position at each date and price in the plan.
Debit spread vs credit spread
The words debit and credit identify entry cash flow. The actual contracts determine the directional payoff. Compare a bull call spread with a bull put spread using the same strikes and expiration, including their quoted entry prices and financing.
A calendar or diagonal also opens for a debit in many configurations. Its different expirations require valuing the remaining option at the first expiration. Apply the width-minus-debit formula specifically to the matching-expiration vertical described here.
Managing a debit spread and assignment
Use a combined order with a net debit limit. To exit, sell the long option and buy back the short option together.
Plan the shares created by exercise and assignment when holding through expiration. Shares retained after the options expire form a separate position with their own P&L.
Risks and limitations of debit spreads
- Size the spread from the full debit, which is lost if the stock finishes on the wrong side of the long strike: $250 in the example at $100 or lower.
- Place the short strike at your target, because it caps the gain. Above $110 at expiration the spread holds at its $1,000 width, so a larger move earns no more than $750.
- Read time decay from the net theta of both legs at the current price, volatility and time. To earn a profit at expiry, a bullish spread needs the stock above its expiration breakeven; a bearish spread needs it below.
- Plan for early assignment on the short leg. An American-style short option can be assigned early, which creates a stock position while the long option stays open.
- Enter and exit with one net limit order. Two legs pay two bid-ask spreads on entry and exit, and those costs raise the effective debit and move the breakeven further from the long strike.
Bottom line
A debit spread puts a fixed price on a target, $2.50 for the move from 100 to 110, and that $2.50 is the maximum loss. Put the short strike at your target, and weigh the cheaper entry against the gain you give up past it.
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Sources and Further Reading
How entries are sourced, calculated and updated: editorial methodology.