Options are among the most versatile instruments available to individual investors. This article introduces the foundational concepts you need before exploring any other options topic on Ainvest.

The Basic Definition

An option is a financial contract that gives the buyer the right, but not the obligation, to buy or sell an underlying asset at a specified price (the strike price) before or on a specified date (the expiration date). In exchange for this right, the buyer pays a fee called the premium to the seller.

The seller (also called the writer) takes on the obligation to fulfill the contract if the buyer chooses to exercise. Sellers collect the premium as compensation for accepting this obligation.

Two Types of Options

  • Call options give the buyer the right to buy the underlying asset at the strike price.
  • Put options give the buyer the right to sell the underlying asset at the strike price.

These two contract types are explored in depth in Calls vs Puts.

Key Terms

Term Definition
Underlying asset The stock, ETF, or index the option is based on (e.g., SPY, AAPL).
Strike price The price at which the buyer can buy (call) or sell (put) the underlying.
Expiration date The last date the option can be exercised. After this date, the contract ceases to exist.
Premium The price paid by the buyer to the seller for the option contract.
Contract One standard equity option contract represents 100 shares of the underlying asset.

Why Traders Use Options

Options serve four primary purposes:

Leverage. A single option contract controls 100 shares of stock. This lets you gain exposure to a stock's movement for a fraction of the cost of buying the shares outright. A $500 option position might give you exposure equivalent to $70,000 worth of stock.

Hedging. If you own shares and are worried about a short-term decline, you can buy put options to protect your downside. This acts like an insurance policy on your position.

Income generation. Selling options allows you to collect premium. Strategies like covered calls and cash-secured puts are popular among investors who want to generate regular income from their portfolios.

Speculation. Traders use options to profit from directional moves, volatility changes, or time decay -- often with a defined and limited risk.

Options Are Wasting Assets

Unlike stocks, options have a limited lifespan. Every day that passes, the option loses a small amount of value due to time decay (also known as theta). All else being equal, an option is worth less tomorrow than it is today. This is one of the most important dynamics for new options traders to understand: time works against option buyers and in favor of option sellers.

A Simple Example

Suppose SPY is trading at $693 and you believe it will rise in the next two weeks. You buy a call option with a $695 strike price expiring in 14 days. The premium is $2.23 per share.

  • Total cost: $2.23 x 100 shares = $223 (this is the maximum you can lose)
  • Breakeven at expiration: $695 + $2.23 = $697.23

If SPY rises to $700 by expiration: The option has at least $5.00 of intrinsic value ($700 - $695). Your contract is worth at least $500. Your profit is $500 - $223 = $277, a return of 124% on your investment.

If SPY stays below $695 at expiration: The option expires worthless. Your loss is the full premium paid: $223.

This asymmetric payoff -- limited downside, amplified upside -- is one of the core attractions of buying options.

Where to Find This on Ainvest

  • Option Chain: Displays all available contracts for a given ticker, organized by expiration date and strike price. This is where you browse real-time premiums, strikes, and expirations.
  • Strategy Builder: Lets you model potential outcomes visually, including profit/loss at various price levels and dates.

Try it on Ainvest:

Next Steps

  • Calls vs Puts -- Understand the two contract types in detail.
  • Glossary -- Quick-reference definitions for all options terminology.