Bear Put Spread

A bear put spread purchases a put and sells another put at a lower strike on the same underlying. Equal quantities, matching contract sizes, and a common expiration create a vertical spread with a net debit and finite maximum profit and loss. The lower-strike sale reduces the purchase cost in exchange for offsetting further expiration gains below the short strike.

The position provides bearish exposure through the interval between the strikes. Unlike a standalone long put, it stops gaining from a further decline once both puts’ payoff difference has reached the strike width.

Construction and example

A hypothetical example uses SPY at $750 and puts with 45 days remaining. Purchasing one $750 put for $16 per share and selling one $725 put for $6.50 produces a $9.50 per-share net debit. One standard 100-share contract in each leg makes the initial cost $950. The premium received for the lower put offsets part of the higher put’s cost but creates a separate purchase obligation.

Expiration payoff

At $750 or above at expiration, neither put has intrinsic value and the full $950 debit is lost. Between $750 and $725, the higher-strike purchased put gains value as SPY declines while the short put still has zero payoff. Each $1 decline adds $100 to the spread’s payoff.

At $745, the purchased put pays $5 per share, or $500. Subtracting the $950 debit leaves a $450 loss. The position breaks even at $740.50, where the $9.50 per-share intrinsic value recovers the entry cost.

At $725, the higher put pays $25 per share and the lower put has zero payoff. Below that price, both puts gain intrinsic value at the same rate, leaving a constant $25 difference. The spread’s maximum payoff is therefore $2,500, and its maximum profit after the $950 debit is $1,550, or $15.50 per share.

The lower-strike sale reduces the cost of downside exposure but gives up additional profit after a sufficiently large decline. Changing that strike changes both the credit received and the width over which the long put can gain without an offsetting short payoff.

Value before expiration

Closing the spread sells the $750 put and buys back the $725 put. A net receipt greater than the $9.50 per-share opening debit produces a profit. Both premiums can contain time value, so their market-price difference can remain below $25 even after SPY has fallen through both strikes.

A decline generally increases the higher put’s value more than the lower put’s value, improving the spread. As both move deeply into the money, their responses become more alike and the combined value approaches its maximum expiration payoff. The price effect of further declines consequently becomes smaller for the spread than for an unhedged put.

Time has different implications across the price range. With SPY well above $750, a shorter remaining term reduces the opportunity for a profitable decline. Well below $725, it reduces the opportunity for a recovery that would lower the final spread value. Volatility changes also affect the puts differently. An increase concentrated in the lower-strike put’s IV enlarges the short obligation and can offset part of a favorable underlying decline.

Exercise, assignment, and execution

SPY puts permit early exercise. Assignment of the short $725 put purchases 100 shares at $725 while the purchased $750 put remains a sale right. Exercising that put to sell the acquired shares realizes the $25 strike difference before the entry debit. Selling the shares and the put instead can recover remaining time value when suitable market prices are available.

At expiration between the strikes, the $750 put can be exercised while the $725 put expires unused. A holder without shares to deliver may be left with short stock, subject to account permissions. That short position has its own exposure to a later rise and needs a separate purchase to close. The spread’s expiration bounds do not limit losses from shares retained after the options end.

A complex order can close both option legs at a net price in the specified one-to-one ratio. Separate-leg trades expose the account to price changes between fills and to an interim position different from the completed spread. Package execution addresses the filled quantity but does not guarantee a complete fill or combine the exercise decisions.

Payoff formulas

Let $K_H$ be the higher purchased strike, $K_L$ the lower short strike, $d$ the debit per share, and $S_T$ the final underlying price. The result adds the higher put’s payoff, subtracts the lower put’s payoff, and deducts the entry debit. For $q$ complete spreads with multiplier $M$:

For positive strikes and a positive debit smaller than their width:

The break-even lies between the strikes, where the purchased put alone supplies enough payoff to recover the debit. Below both strikes, the payoff difference equals the width; above both, it is zero. Scaling complete spreads changes dollar results proportionately without changing these price regions.