Glossary term
Short Put
A short put is an options position created by selling a put option and taking on the obligation to buy the underlying asset if assigned.
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What Is a Short Put?
A short put is an options position created by selling, or writing, a put option. The seller receives a premium and takes on the obligation to buy the underlying asset at the strike price if the option is exercised or assigned.
The position is generally bullish to neutral. The seller benefits if the underlying price stays above the strike price and the option expires worthless. The risk is that the underlying price falls sharply, forcing the seller to buy at a strike price above market value.
Key Takeaways
- A short put means selling a put option and receiving premium upfront.
- The seller may be obligated to buy the underlying asset at the strike price.
- Maximum profit is usually limited to the premium received.
- Downside risk can be substantial if the underlying asset falls sharply.
- Cash-secured puts and naked short puts have very different risk profiles.
How a Short Put Works
When an investor sells a put, another party buys the right to sell the underlying asset at the strike price. If the asset stays above the strike price through expiration, the put may expire worthless and the seller keeps the premium. If the asset falls below the strike price, the seller may be assigned and required to buy the asset.
The seller's effective purchase price, if assigned, is the strike price minus the premium received. That can make short puts attractive to investors willing to buy a stock at a lower effective price. It can be dangerous when the seller is mainly chasing premium without being prepared to own the asset or absorb losses.
Example
Suppose a stock trades at $50. An investor sells a put with a $45 strike and receives a $2 premium. If the stock stays above $45, the option may expire worthless and the investor keeps $2 per share. If the stock falls to $38 and assignment occurs, the investor buys at $45, with an effective cost of $43 after the premium.
The premium cushions the loss but does not eliminate it. If the stock keeps falling, the short put behaves economically like a commitment to buy a declining asset at a fixed price.
Cash-Secured Versus Naked Short Put
Structure | How it is funded | Risk profile |
|---|---|---|
Cash-secured put | Seller holds enough cash to buy if assigned | Risk resembles buying the stock at the effective price |
Naked short put | Seller does not set aside the full purchase amount | Greater liquidity and margin risk if the asset falls |
A cash-secured put can be a disciplined entry strategy when the seller genuinely wants to own the underlying asset. A naked short put can create forced-liquidation risk if losses or margin requirements rise quickly.
Profit and Loss
The maximum profit on a simple short put is the premium received. The breakeven price is the strike price minus the premium. Losses grow as the underlying asset falls below breakeven. For stock options, the theoretical downside extends until the stock reaches zero.
Time decay can help the seller because option value may decline as expiration approaches, all else equal. Volatility can hurt the seller because higher expected volatility can increase the value of the put and the risk of assignment.
Position sizing is central. A short put on a stock the seller is willing and able to buy can be part of a disciplined options plan. Selling too many puts, or selling puts on weak assets only because premiums look attractive, can create losses that arrive suddenly when markets fall and liquidity becomes more valuable.
The Bottom Line
A short put can generate premium income or create a disciplined way to buy an asset at an effective discount. It is not a free-income trade. The seller is being paid to accept downside risk and must be ready for assignment, margin pressure, and real losses if the underlying asset falls.