What Is an Option? Call, Put, Long, Short, and Premium Explained

Forwards and futures obligate both sides. At maturity, both parties must perform, regardless of whether doing so means taking a loss.

Options work differently.

An option is a financial derivative that gives the holder the right, but not the obligation, to buy or sell an underlying asset at a predetermined price on or before a predetermined date.

At expiry, the holder looks at the situation and decides: execute, or walk away. If executing means a loss, they walk away. Nothing forces them to perform.

What Every Option Contract Contains

Every option has five components.

Underlying asset. The asset the option is linked to: a stock, commodity, currency, bond, or index.

Strike price. The predetermined price at which the holder can buy or sell the underlying. Same concept as in futures and forwards.

Premium. The price the buyer pays to the seller to own the option. This flows only one direction: from buyer to seller, always, without exception. More on why below.

Expiration date. The date by which the option must be exercised. If the holder does not exercise by this date, the option expires worthless.

Exercise style. The rules for when exercise is permitted. There are two main styles.

American vs European Options

An American option can be exercised at any point before expiry. If you hold an American option and see a profitable moment on day 30 of a 90-day contract, you can exercise immediately without waiting for the end.

A European option can only be exercised at maturity. You hold it to the end, then decide. Profitable: execute. Not profitable: let it expire.

The names have nothing to do with geography. They describe only when exercise is permitted.

Call Options and Put Options

There are two types of options.

A call option gives the holder the right to buy the underlying asset. The natural question: when would someone want to buy? When they expect the price to go up. A call option is a position built on the expectation that the underlying price will rise.

A put option gives the holder the right to sell the underlying asset. When would someone want to sell? When they expect the price to fall. A put option is a position built on the expectation that the underlying price will decline.

Both types can be bought or sold. That gives four possible positions.

The Four Positions

Long call: You bought a call option. You have the right to buy the underlying. You expect the price to rise. If it does, you execute. If it does not, you walk away. You only lose the premium you paid upfront.

Short call: You sold a call option. You have no choice. If the buyer decides to execute, you are obligated to sell the underlying at the strike price. Your expectation was that the price would stay flat or fall.

Long put: You bought a put option. You have the right to sell the underlying. You expect the price to fall. If it does, you execute and sell at the higher predetermined price. If prices rise instead, you walk away.

Short put: You sold a put option. If the buyer exercises, you are obligated to buy the underlying at the strike price. Your expectation was that the price would stay flat or rise.

The pattern is consistent. Long always has a choice. Short is always obligated.

Why the Buyer Always Pays Premium

The long position has a clear advantage: the ability to walk away when the trade goes against them. The short position has no such advantage. Whatever the buyer decides, the seller must honor.

That asymmetry has a price. The buyer pays it to the seller upfront, before any trade takes place. This payment is the premium.

Think of it this way: the premium is the cost of having a safety net. The seller accepts obligation in exchange for receiving the premium. The buyer pays for the freedom to choose.

Long always pays premium. Short always receives it. This holds for every option contract, on every exchange, in every market.

The Essentials

An option gives the right, not the obligation. The holder can choose at expiry whether to execute the contract. If executing means a loss, they walk away. Forwards and futures offer no such exit.
Call options are the right to buy; put options are the right to sell. Long call expects the price to rise. Long put expects the price to fall. Short positions on both are obligations.
The buyer always pays premium to the seller. This compensates the seller for being obligated regardless of outcome. The buyer gains the freedom to choose; the seller loses it. Premium is the price of that asymmetry.

The payoff diagrams for call and put options look very different from the straight lines of futures and forwards. The next post works through all four positions with numbers and diagrams.