Put option
What is Put option?
A put option gives its buyer the right to sell an underlying asset or receive an equivalent cash payoff at a specified strike under the contract's terms.
Put protection should be evaluated as insurance with a defined attachment point, term, basis, and recurring cost. A hedge can work contractually yet disappoint if it covers the wrong index, expires before the loss, or is too small. Portfolio analysis should compare protective puts, reduced exposure, diversification, spreads, and liquidity reserves under the same downside and recovery scenarios.
Put payoff
At expiration, a standard long put's intrinsic value is the greater of strike minus underlying price or zero. Profit subtracts premium and costs. The short put has the opposite contractual payoff and can incur a large loss if the underlying collapses. Before expiration, time, volatility, rates, dividends, and exercise expectations affect value.
Example
An investor buys a $50 strike put for $2 with a 100-share multiplier, paying $200. If stock ends at $40, exercise value is $1,000 and profit before costs is $800. At or above $50, the put expires worthless. Break-even at expiration is $48, but mark-to-market profit can differ beforehand.
Common uses
A protective put can limit downside on owned shares while preserving upside, at the cost of premium. Puts can express bearish views, hedge portfolios, or form spreads. Selling cash-secured puts may be intended to acquire stock, but still exposes the seller to severe loss and opportunity cost when fundamentals deteriorate or price gaps.
Sensitivity and valuation
A long put generally has negative delta, positive gamma, positive vega, and negative theta. Downside skew often makes equity puts relatively expensive in implied-volatility terms. That premium can reflect demand and crash risk rather than a pricing error. Analyze the full volatility surface, expected dividends, borrow, rates, and discrete event exposure.
Risks and practical checklist
Long puts can lose all premium and may not hedge perfectly because of strike, maturity, basis, or position size. Short puts can create large obligations. Confirm underlying, multiplier, exercise, settlement, expiration, deliverable, margin, and assignment. Match hedge horizon and quantity, stress gaps, and compare recurring premium cost with other risk reductions instead of calling protection either free or wasteful.
Sources and further reading
- Investor Bulletin: An Introduction to Options, Investor.gov, U.S. Securities and Exchange Commission