Call Option

A call option is one of the two fundamental building blocks of options trading on U.S. exchanges such as the Chicago Board Options Exchange (CBOE). When you buy a call option, you are purchasing the contractual right to acquire 100 shares of the underlying equity at the agreed strike price, regardless of where the stock trades in the open market. That right persists until the contract expires, but you are never forced to exercise it — hence 'option.' The most you can lose as a buyer is the premium paid upfront.

Call options become profitable when the underlying stock rises above the strike price by more than the premium paid. Suppose shares of a technology company trade at $150. You buy one call contract with a $155 strike expiring in 60 days for a premium of $3.00 per share, or $300 total (100 shares x $3.00). If the stock climbs to $165, your option has $10 of intrinsic value. You could exercise to buy 100 shares at $155 and immediately sell at $165, netting $1,000 minus the $300 premium, a profit of $700. Alternatively, you could sell the contract back into the market for roughly $10 or more and capture the same gain without touching the shares.

Call options are described as 'American-style' on most U.S. equity markets, meaning the holder can exercise the contract on any trading day up to and including expiration — not just on the expiration date itself. This flexibility commands a slightly higher premium compared to European-style contracts (common in index options) that only allow exercise at expiration.

Sellers (writers) of call options take the opposite position. A call writer receives the premium immediately but accepts the obligation to deliver 100 shares at the strike price if assigned. Uncovered (naked) call writing carries theoretically unlimited risk, since a stock can rise without bound. Covered call writing — selling calls against shares already owned — is a popular income strategy that caps upside in exchange for premium income.

Call options serve many purposes beyond speculation: portfolio managers use them to gain leveraged equity exposure without committing full capital; corporate insiders hedge concentrated positions; and income investors layer covered calls onto long-term holdings to reduce effective cost basis over time. Understanding calls is therefore essential groundwork before exploring more complex multi-leg strategies.