Trading · Options basics
Vertical spreads: bull call, bear put and credit spreads explained
How vertical option spreads work, how to compute maximum profit, maximum loss and break-even for debit and credit spreads, and the risks that remain.
On this page
A vertical spread is two options of the same type, on the same stock, with the same expiration, but at different strikes: you buy one and sell the other. "Vertical" comes from old printed option tables, where strikes ran down the page, so the two legs sat one above the other. Combining the legs caps both the most you can make and the most you can lose, which is why verticals are among the most widely used multi-leg positions.
There are four basic verticals, two built with calls and two with puts. Two of them cost money up front (debit spreads) and two pay money up front (credit spreads). Two profit from a rise (bull spreads) and two from a fall (bear spreads). Once you see that every vertical is just a long option partly paid for, or a short option partly insured, the arithmetic for all four comes down to three formulas. This page derives them, works through examples with illustrative prices, and covers the risks that remain even with a defined maximum loss.
The four verticals
| Spread | Legs (same expiration) | Net premium | Profits if the stock | Also called |
|---|---|---|---|---|
| Bull call | Buy lower-strike call, sell higher-strike call | Debit | Rises | Debit call spread |
| Bear put | Buy higher-strike put, sell lower-strike put | Debit | Falls | Debit put spread |
| Bull put | Sell higher-strike put, buy lower-strike put | Credit | Holds or rises | Credit put spread |
| Bear call | Sell lower-strike call, buy higher-strike call | Credit | Holds or falls | Credit call spread |
The rule of thumb for which side is bought: in a debit spread, you buy the option that is closer to the money (the more expensive one) and sell the cheaper one to reduce the cost. In a credit spread, you sell the option closer to the money and buy the cheaper one further out as protection.
The arithmetic
At expiration, a vertical spread is worth somewhere between zero and its width, the difference between the two strikes. That single fact produces every number you need.
A quick check: in every vertical, max profit plus max loss equals the width. The spread can never be worth more than the width, nor less than zero.
Bull call spread
The chart shows the trade-off against buying the $100 call alone. The spread costs $1.50 less, so it loses less if the stock goes nowhere ($250 against $400) and breaks even sooner ($102.50 against $104). In exchange, its gain stops at $110, where the lone call keeps climbing. Selling the higher call also reduces the position's exposure to time decay and to implied volatility, because the two legs partly offset each other.
Bear put spread
The mirror image for a falling stock.
Credit spreads: bull put and bear call
A credit spread starts by selling an option, which pays a premium, and then buys a cheaper, further out-of-the-money option of the same type to cap the loss. The premium kept is the reward; the width minus that premium is the risk.
Credit spreads and debit spreads are two ways of expressing a similar view. A bull put spread and a bull call spread on the same pair of strikes have almost the same payoff shape; one is paid for up front and the other collects up front, and the difference between them is mostly the interest on the cash. What differs most is where the strikes sit relative to the stock and therefore the odds: credit spreads are usually placed out of the money, so they win small amounts often and lose larger amounts less often.
Collateral
In a US margin account, as of 2026, FINRA Rule 4210 sets a spread's margin requirement by the strike difference rather than treating the short leg as uncovered. In practice a broker holds roughly the maximum loss: the width × 100 for a credit spread, against which the credit received is applied, and the debit itself for a debit spread. Each firm can require more than the rule's minimum, and brokers generally reserve spreads for a middle tier of options approval.
Risks that remain
Early assignment on the short leg. US stock options are American-style, so the option you sold can be exercised against you before expiration. The long leg still protects you, but you may end up with a stock position overnight, need cash or margin to carry it, and have to exercise or sell the long leg to close out. Short calls in spreads are most exposed the day before an ex-dividend date when they are in the money and have little time value.
Pin risk at expiration. If the stock closes between the strikes, or right at the short strike, you may not know whether your short leg will be exercised. The long leg protects you only if you act on it; if it is out of the money and expires, while the short leg is assigned, you can wake up with 100 shares, long or short, and no hedge. Option exercise and assignment: how it works and when it happens explains how the 5:30 p.m. Eastern exercise cut-off creates that uncertainty.
Losing the whole debit or the whole width. Defined risk is still risk. A debit spread loses 100% of its cost if the stock does not move in time, and a credit spread's maximum loss is usually several times its maximum profit.
Two bid-ask spreads. Every leg has its own bid and ask, so the cost of trading a vertical is higher than a single option. On thinly traded strikes the round-trip cost can be a large share of the maximum profit.
Closing early rarely captures the full maximum. Before expiration a spread is worth less than its width even when both legs are deep in the money, because the short leg still carries some time value. Traders who close early typically capture only part of the theoretical maximum.
The four compared
| Spread | Up front | Max profit | Max loss | Break-even | Helped by time decay? |
|---|---|---|---|---|---|
| Bull call | Pay | Width − debit | Debit | Lower strike + debit | Usually no |
| Bear put | Pay | Width − debit | Debit | Higher strike − debit | Usually no |
| Bull put | Receive | Credit | Width − credit | Higher strike − credit | Usually yes |
| Bear call | Receive | Credit | Width − credit | Lower strike + credit | Usually yes |
Whether time decay helps depends on where the stock sits against the strikes; the last column describes the common case where the debit spread is bought around the money and the credit spread is sold out of the money.
How Finabase helps
A Finabase option chain such as QQQ options shows every strike for one expiration in a single table, with calls on the left and puts on the right, so both legs of a vertical are visible side by side. Each row carries bid, ask, last price, change, volume, open interest and implied volatility, and the strikes-each-side control widens the view from 5 strikes around the current price to 10, 20, 50 or all. With the bid and ask of each leg you can estimate a spread's net debit or credit and work out the maximum profit, maximum loss and break-even with the formulas above. Signed-in users can star both legs to follow them on the options page. Quotes come from a data provider and may be delayed, and Finabase does not place orders.
Frequently asked questions
What is the difference between a debit spread and a credit spread?
A debit spread costs money to open and has its maximum loss equal to that cost. A credit spread pays money to open and has its maximum profit equal to that credit. Both have a maximum profit plus maximum loss equal to the width between the strikes.
Can you lose more than the maximum loss on a vertical spread?
At expiration, with both legs held, no: the spread's value is bounded by zero and the width. Practical exceptions come from early assignment, pin risk when one leg is exercised and the other is not, and the costs of closing positions.
Why sell a call against a long call instead of just buying the call?
Selling the higher-strike call lowers the cost and break-even of the trade and reduces exposure to time decay and volatility. The price is a capped maximum profit.
Which expiration do both legs use?
The same one. Spreads with different expirations are calendar or diagonal spreads, which behave quite differently because the two legs decay at different speeds.
Summary
A vertical spread pairs a bought and a sold option of the same type and expiration at two strikes. Debit spreads cost money and risk only that cost; credit spreads collect money and risk the width minus the credit. Max profit plus max loss always equals the width, and the break-even sits one premium away from the strike you bought or sold. The structure defines risk at expiration, while early assignment, pin risk and trading costs remain real along the way.