The basics of options
The four fundamental characteristics that make up an option contract are action, type, expiration, and strike price.
Key terms
- Action: whether the contract is bought (buy) or sold (sell). Buying an option gives you the right to exercise; selling an option creates an obligation if assigned
- Type: indicates whether the option is a Call (right to buy the underlying) or a Put (right to sell the underlying)
- Expiration: the date the option contract ceases to exist; after this date the contract is either exercised, assigned, or expires worthless
- Strike price: the agreed upon price at which the underlying asset can be bought (call) or sold (put) if the option is exercised
How these fields affect a trade
- Choosing buy vs sell determines whether you hold a right (long) or an obligation (short), which affects risk and margin
- Selecting Call vs Put defines the directional expectation required for a position to gain value
- Expiration affects time value (Theta) and exercise/assignment risk; shorter expirations accelerate time decay
- Strike price determines moneyness (in-the-money, at-the-money, out-of-the-money) and is central to payoff shape and breakeven points


