Learn How to Trade Bull Put Spreads for Income with Limited Risk

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A bull put spread is a two-leg options strategy that sells a put option at a higher strike price and buys a put option at a lower strike price, on the same underlying and with the same expiration date. The sold put brings in more premium than the bought put costs, so the trader opens the position for a net credit. That credit is the most the trade can earn. The gap between the two strikes, minus that credit, is the most it can lose. Because the position profits when the underlying rises, holds steady or falls only slightly, it is also called a bull credit spread or a short put spread.

How a Bull Put Spread Works

A put option gives its buyer the right to sell the underlying at the strike price. The seller (the writer) collects a premium and takes on the obligation to buy the underlying at the strike if the holder exercises. If the underlying trades above the strike at expiration, the put expires worthless and the writer keeps the premium. If it falls below the strike, the put has intrinsic value and the writer may have to buy shares above where they trade.

A bull put spread combines both roles:

1. Sell one put at the higher strike. This is the income leg. It carries the larger premium because it sits closer to the current price.
2. Buy one put at the lower strike. This is the protection leg. It costs less, and it gives you the right to sell at the lower strike, which offsets losses on the short put once the price drops below that level.

Both legs share the same expiration and normally the same number of contracts. In the most common setup, both strikes are below the current price, so both puts start out of the money. Placing the short strike closer to the current price, or even above it, raises the credit but also raises the chance that the short put finishes in the money.

Equity options in the US typically represent 100 shares per contract, so a per-share credit of $1.00 becomes $100 per spread.

Bull Put Spread Formulas

All figures below are per share, assume one long and one short contract held to expiration, and exclude commissions and fees. Multiply by 100 (or the contract multiplier) for dollar amounts.

• Net credit = premium received for the higher-strike put − premium paid for the lower-strike put
• Maximum profit = net credit
• Strike width = higher strike − lower strike
• Maximum loss = strike width − net credit
• Breakeven = higher strike − net credit

The maximum profit plus the maximum loss always equals the strike width. A wider spread or a smaller credit means more capital at risk per dollar of potential income.

Interpreting the Payoff

The payoff chart for a bull put spread has three zones:

• At or above the higher strike: both puts expire worthless. You keep the entire credit. Further gains in the underlying add nothing.
• Between the two strikes: the short put is in the money and the long put is not. The short put’s intrinsic value (higher strike minus the closing price) eats into the credit. Above breakeven you still keep part of the credit; below breakeven you take a partial loss.
• At or below the lower strike: both puts are in the money. Any additional decline is offset dollar for dollar by the long put, so the loss stays fixed at the maximum.

Bull Put Spread Example

In this hypothetical example with illustrative prices, a stock trades at $50. A trader expects it to hold above $48 over the next month and opens a bull put spread:

• Sells one $48 put expiring in 30 days for $1.60
• Buys one $45 put with the same expiration for $0.60

Net credit: $1.60 − $0.60 = $1.00 per share, or $100 per spread. Strike width: $48 − $45 = $3.00. Maximum loss: $3.00 − $1.00 = $2.00 per share, or $200. Breakeven: $48 − $1.00 = $47.00.

Scenario 1: Maximum Profit

The stock closes at $52 at expiration. Both puts are out of the money and expire worthless. The trader keeps the full $100. The result would be identical at $48.01 or at $70; the profit is capped at the credit.

Scenario 2: Partial Loss Between the Strikes

The stock closes at $46.50. The $48 put is worth $1.50 in intrinsic value; the $45 put is worthless. The position owes $1.50 against a $1.00 credit, for a loss of $0.50 per share, or $50. At exactly $47.00 the trade breaks even.

Scenario 3: Maximum Loss

The stock closes at $44. The $48 put is worth $4.00 and the $45 put is worth $1.00, so the spread is worth $3.00 against the trader. Subtracting the $1.00 credit leaves a loss of $2.00 per share, or $200. If the stock had fallen to $30, the loss would still be $200, because the long $45 put gains whatever the short $48 put loses below $45.

In this example the trader risks $200 to make $100. The closer the short strike is to the current price, the larger the credit relative to the width, but the less room the stock has to fall before the trade loses money.

How to Sell Put Spreads: Building the Trade

Choose the underlying and outlook. The strategy fits a neutral-to-moderately-bullish view. If you expect a strong rally, a bull call spread or a long call keeps more upside. A straddle or strangle addresses volatility rather than direction.

Pick the short strike. This is the level you expect the price to stay above. Many traders use a support level or the option’s delta as a rough guide. Delta is often read as an approximate probability that the option finishes in the money, though it is a pricing sensitivity and not a forecast.

Pick the long strike. The distance between strikes sets the maximum loss. A narrow spread risks less per contract but collects less. A wide spread collects more but risks more.

Pick the expiration. Shorter expirations decay faster but leave less time for the thesis to work and react more sharply to price moves. Longer expirations collect more premium in absolute terms but keep capital tied up longer.

Enter as a single order. Most platforms let you place both legs together as a vertical spread at a net credit limit price. Entering the legs separately exposes you to the price moving between fills.

Plan the exit. Many credit spread traders close the position before expiration rather than waiting for the last few cents of premium while still carrying full downside risk. You buy back the short put and sell the long put, usually as one spread order for a net debit; your profit or loss is the original credit minus that debit, less fees. Closing early also removes assignment risk.

What Drives the Spread’s Value Before Expiration

Before expiration, the spread’s value moves with the option Greeks:

• Delta is positive: the position gains as the underlying rises.
• Theta is generally positive when the price is above the short strike: time decay erodes the value of the sold put faster than the bought put, which works in the seller’s favor.
• Vega is generally negative: a rise in implied volatility increases put prices and makes the spread more expensive to buy back.
• Gamma is generally negative near the short strike: delta changes faster as the price approaches that strike, so the position’s sensitivity can shift quickly late in the option’s life.

These sensitivities come from pricing models such as the Black-Scholes model. They explain why a spread can show a paper loss before expiration even if the stock never closes below the short strike.

Limitations and Risks

Capped upside. The credit is the ceiling. If the stock rallies hard, the trader earns the same as if it had barely moved and misses the rest of the gain.

Unfavorable risk-to-reward. The maximum loss usually exceeds the maximum profit, so a few losing trades can erase many winners.

Early assignment. American-style equity options can be exercised at any time. If the short put goes deep in the money, you may be required to buy 100 shares per contract at the higher strike. The long put still caps your loss at the defined maximum, but you need the cash or margin to carry the stock until you sell it or exercise or sell the long put. Index options are commonly European-style and cash-settled, which removes early assignment.

Expiration risk. If the price closes between the strikes, the short put may be assigned while the long put expires worthless, leaving you with a stock position over the weekend. Closing the spread before expiration avoids this.

Costs and margin. Options trades generally carry per-contract fees or commissions even where stock trades are commission-free, and with two legs, costs apply twice on entry and again on exit. The margin requirement for a defined-risk spread is generally tied to the maximum loss, though rules vary by broker and account type, and spreads may need a margin account or a specific options approval level.

Bull Put Spread vs. Similar Strategies

Bull put spread vs. short (naked) put. Selling a put by itself collects more premium but exposes you to losses down to a stock price of zero. The bull put spread gives up part of the premium to buy a floor under that loss.

Bull put spread vs. bull call spread. Both are bullish verticals with capped profit and loss. A bull call spread buys a lower-strike call and sells a higher-strike call for a net debit, so the trader pays up front and needs the price to rise toward the higher strike. A bull put spread collects a credit and profits if the price simply stays above the short strike. With identical strikes and expiration the payoff shapes are similar; the difference is cash flow at entry and how time decay affects each.

Bull put spread vs. bear put spread. A bear put spread uses the same two strikes in reverse: buy the higher-strike put, sell the lower-strike put, for a net debit. It profits from a decline. Put spreads are not inherently bullish or bearish; the direction depends on which strike you sell.

Bull put spread vs. bear call spread. A bear call spread sells a lower-strike call and buys a higher-strike call for a credit. It is the bearish mirror image: income if the price stays below the short strike.

Bull put spread vs. covered call. A covered call holds the stock and sells a call against it to collect premium. It keeps the full downside of stock ownership, cushioned only by the premium. The bull put spread does not require owning shares and has a defined maximum loss.

Bull put spread vs. bull put ladder. A bull put ladder adds a third leg, typically another long put at an even lower strike, so a sharp drop can become profitable. It is a different strategy with a different payoff, not a variant of the two-leg spread.

The Bottom Line

Options traders with a neutral to moderately bullish view can use a bull put spread to collect income with a defined maximum loss. The tradeoff is capped upside and a loss that usually exceeds the potential gain, so strike placement and width matter. Entering both legs as one order and closing before expiration helps manage fill, assignment and expiration risk.