Vega trader

Call debit spread

A call debit spread (bull call spread) is a two-legged, defined-risk, bullish option strategy. You buy a lower-strike call and sell a higher-strike call with the same expiration, paying a net debit. The chart below shows a call debit spread with long call strike 100 at $5, short call strike 105 at $2, and the profit/loss diagram.

Orders(2)

Profit/Loss chart

At expiration Mark-to-market (model)
$-380.00$-297.50$-215.00$-132.50$-50.00$32.50$115.00$197.50$280.00 $83.21$87.58$91.95$96.32$100.69$105.06$109.43$113.80$118.17$122.54 $103.00
5% 150%
0 30

The smooth curve uses Black–Scholes (European-style, flat rate); adjust IV and time to explore sensitivity. Does not model dividends or early exercise.

1% 100%
Increases or decreases the price range on the chart for better overview

Greeks and this strategy

Greek How it behaves
Delta Positive. Net bullish exposure, but capped by the short higher-strike call.
Theta Negative. Time decay erodes the spread when the stock does not rise.
Gamma Positive but lower than a naked long call. Delta increases on rallies but caps at expiration.
Vega Positive. Rising implied volatility generally increases spread value; falling volatility hurts.

Overview of call debit spread

A call debit spread combines a long call at a lower strike with a short call at a higher strike. The short call reduces the cost of the long call and caps maximum profit at the spread width minus the net debit paid. Maximum loss is limited to the net debit. Each contract represents 100 shares of the underlying (relevant for the US market).

Market outlook for call debit spread

Traders open a call debit spread when they expect the underlying price to rise moderately before expiration. Unlike a long call, the short higher-strike call limits upside but also lowers the entry cost. A narrower spread costs less but offers a smaller profit zone. A wider spread costs more but allows greater profit if the stock rallies strongly.

How to open a call debit spread

Open the position by buying a call at the lower strike and simultaneously selling a call at the higher strike. Both orders are typically placed as a single vertical spread order. The net debit paid is the long call premium minus the short call premium. Strike selection, expiration, and implied volatility determine whether the trade offers favorable risk/reward.

Profit/loss diagram for a call debit spread

Maximum loss equals the net debit paid and occurs if the stock is at or below the long strike at expiration. Maximum profit equals the spread width minus the net debit. For example, buying a $100 call for $5.00 and selling a $105 call for $2.00 creates a $3.00 debit on a $5.00-wide spread. Maximum loss is $300 per contract and maximum profit is $200 per contract. The lower break-even at expiration is the long strike plus the net debit, or $103 in this example.

How to enter a call debit spread

Submit a vertical call debit spread order to your broker, specifying the long and short strikes and a limit price for the net debit. The order is filled when the market accepts your limit debit or better. Opening the spread debits your account for the net premium plus commissions.

How to exit a call debit spread

Close the spread before expiration by selling the long call and buying back the short call as a single order. If the spread value has increased above the entry debit, you realize a profit. At expiration, if the stock is above the short strike, both legs may be exercised or cash-settled according to your broker's rules, delivering the spread's maximum value.

The impact of time decay on a call debit spread

Time decay works against the call debit spread when the underlying remains below the long strike, eroding the value of both calls. However, if the stock rises and both calls retain intrinsic value, time decay has less impact near expiration. Rising implied volatility tends to increase the spread value; falling volatility can reduce it.