What is a Credit Spread Option Strategy? Definition, Formula, and Example
A credit spread is an options strategy in which a trader sells one option and buys another option of the same type and expiration to collect a net premium while capping maximum loss.
Definition
A credit spread is a defined-risk options strategy in which a trader sells an option and simultaneously buys a further out-of-the-money option of the same type and expiration. The short option carries a higher premium than the long option, so the position opens for a net credit. Maximum profit equals the net credit received, and maximum loss equals the width of the spread minus the credit. Credit spreads are used when a trader has a directional bias but wants to limit risk and define the breakeven point before entry.
How it is calculated
For a bull put spread, the trader sells a put at a higher strike and buys a put at a lower strike with the same expiration.
Net credit = Short put premium - Long put premium
Maximum profit = Net credit
Maximum loss = Strike width - Net credit
Breakeven = Short strike - Net credit
For a bear call spread, the trader sells a call at a lower strike and buys a call at a higher strike.
Net credit = Short call premium - Long call premium
Maximum profit = Net credit
Maximum loss = Strike width - Net credit
Breakeven = Short strike + Net credit
Worked example
[MSFT] trades at $420. A trader expects the stock to remain above $400 through expiration. The trader sells the $410 put for $4.50 and buys the $400 put for $2.00, both expiring in 45 days.
Net credit = $4.50 - $2.00 = $2.50 per share, or $250 per contract
Maximum profit = $250 if [MSFT] closes above $410 at expiration
Maximum loss = ($410 - $400) - $2.50 = $7.50 per share, or $750 per contract
Breakeven = $410 - $2.50 = $407.50
If [MSFT] expires at $405, the short put is $5 in the money and the long put is $5 in the money, so the spread expires worth $0 and the trader loses the $250 credit plus the difference between the strikes, capped at $750.
When traders use it
Traders sell credit spreads when implied volatility is elevated and they expect time decay to erode the short option's value faster than the long option's. The strategy is common around earnings when a trader wants directional exposure without unlimited risk. Credit spreads are also used to generate income in range-bound markets. paper trading simulator
Limitations and common misconceptions
A credit spread is not risk-free. The maximum loss can exceed the initial credit by several multiples, particularly on wide strike widths. Early assignment risk exists on the short leg, especially for American-style options with dividends nearby. Traders sometimes assume the net credit is kept regardless of price action, but the credit is only retained if the spread expires out of the money or is bought back for less than the credit received. Buying power reduction is based on maximum loss, not the credit collected.