What Is an Options Contract? Calls and Puts Explained

An options contract gives its holder the right, but not the obligation, to buy or sell a specific number of shares at a fixed price, called the strike price, on or before a set expiration date. That single distinction — a right instead of an obligation — is what separates options from simply buying the stock outright, and it’s why options can be used either to speculate for a much smaller upfront cost or to hedge an existing position against a move you don’t want.

Calls and puts

There are exactly two kinds of options:

• A call option gives the holder the right to buy shares at the strike price. Calls gain value as the underlying stock rises above the strike, since the holder can buy low (at the strike) while the shares are worth more than that on the open market.
• A put option gives the holder the right to sell shares at the strike price. Puts gain value as the underlying stock falls below the strike, since the holder can sell at the strike price even though the market price is lower.

Every option has two sides: the buyer (holder) pays a premium upfront for the right, and the seller (writer) collects that premium in exchange for taking on the obligation to fulfill the contract if the buyer chooses to exercise it.

The four basic positions

Position	You believe	Max loss	Max gain	Obligation if exercised
Buy a call	Price will rise	Premium paid	Unlimited	None — you choose to exercise
Sell a call	Price will stay flat or fall	Unlimited (if uncovered)	Premium received	Must sell shares at strike
Buy a put	Price will fall	Premium paid	Strike price (stock to zero)	None — you choose to exercise
Sell a put	Price will stay flat or rise	Strike price (stock to zero)	Premium received	Must buy shares at strike

Buying an option — call or put — caps your loss at the premium you paid, because you simply let the contract expire worthless if the trade doesn’t go your way. Selling (writing) an option flips that asymmetry: you collect a smaller, fixed premium up front, but you carry the obligation to perform on the other side of the trade if the buyer exercises.

Strike price, premium, and expiration

Three variables define any option contract:

• Strike price — the fixed price at which the underlying can be bought or sold if the option is exercised.
• Premium — the price paid to acquire the option, set by the market based on how likely the option is to become profitable before expiration.
• Expiration date — the last day the option can be exercised. After that, an unexercised option simply expires and becomes worthless.

An option’s premium is driven largely by two things: intrinsic value (how far the strike already is from the current stock price, in the option’s favor) and time value (how much time remains for the stock to move further in the holder’s favor). Time value decays as expiration approaches — a dynamic often called “time decay” — which is why an option that looked cheap can lose value even if the stock price doesn’t move at all.

Why options exist: leverage and hedging

Options serve two very different purposes depending on who’s using them:

Speculation. Because an option’s premium is a fraction of the cost of buying the shares outright, a given move in the stock produces a much larger percentage return (or loss) on the option than on the shares themselves. This leverage cuts both ways, which is exactly why options are considered higher-risk than owning the underlying stock directly.

Hedging. An investor holding shares can buy a put as insurance: if the stock falls, the put gains value and offsets some of the loss on the shares, at the cost of the premium paid — conceptually similar to paying for an insurance policy you hope you never need to use. Puts are sometimes compared to short selling since both profit from a falling price, but a put’s loss is capped at the premium paid, while a short position’s loss is theoretically unlimited if the stock rises instead.

Options vs owning the stock

The most common point of confusion is how publicly traded options differ from employee equity like stock options granted as compensation, which is a related but distinct concept. A traded options contract is bought and sold on an exchange between investors, expires on a fixed date, and its value depends heavily on time remaining and volatility, not just the direction of the underlying stock. Buying the stock directly, by contrast, never expires and its value tracks the company’s market capitalization and business performance directly, without the added complexity of a strike price or expiration. Note also that holding an option doesn’t entitle you to receive any dividends the company pays while you hold it — only owning the shares themselves does that.

The takeaway

An options contract separates the right to buy or sell from the obligation to do so: calls profit from a rise above the strike, puts profit from a fall below it, and the premium paid (or collected) reflects both how close the stock already is to being profitable and how much time remains for it to get there. Buying an option caps your risk at the premium; selling one collects a smaller premium in exchange for open-ended obligation. Whether that tradeoff makes sense depends entirely on whether you’re speculating on a move or hedging one you already have exposure to.