™Stock Market University · Derivatives & Volatility
Calls and Puts, Explained
Understand the mechanics and risks.
A risk-aware introduction to option rights, obligations, strike prices and expiration.
The idea to understand
Distinguish buyer rights from seller obligations and calculate expiration payoff, net profit and break-even for a basic long option.
The explanation
The essentials, explained.
Follow the idea, then work through an example. Pause at the self-check whenever you are ready.
An option is a contract
For physically settled contracts, a call gives its holder the right to buy and a put the right to sell the specified underlying at the strike. American-style exercise can occur before expiration; European-style exercise is restricted to expiration. Cash-settled contracts instead pay a contractual cash amount.
Buyers and sellers differ
The buyer pays a premium for a right. The seller receives the premium and accepts an obligation if assigned. Those payoff profiles and risks are not the same.
Work the complete payoff
A call with a $100 strike purchased for a $5 premium has a $105 break-even at expiration before other costs. If the stock ends at $103, the call has $3 per share of intrinsic value—$300 for one standard 100-share contract—but the $500 premium leaves the buyer with a $200 net loss.
Time and volatility matter
An option’s value can change with the underlying price, time remaining, expected volatility, rates and other inputs. Options can expire worthless and some strategies involve substantial risk.
A contract has two sides
The buyer pays a premium for a right; the seller receives premium and accepts an obligation. Maximum gain, maximum loss, break-even and assignment risk differ by position. Describing an option only as a directional bet misses time decay, volatility and the asymmetric responsibilities of buyers and sellers.
Correct direction can still lose
An underlying asset may move in the expected direction while an option loses value because the move was too small, arrived too late or was offset by declining implied volatility. Before using options, understand expiration, contract multiplier, liquidity and the full payoff—not only the premium displayed.
Optional context & practice
Why this matters
An option’s right, premium and multiplier determine a different payoff from the underlying share. Writers also face obligations and assignment risk.
Useful vocabulary
Call option: A contract generally giving the buyer the right, but not the obligation, to buy at the strike price. Put option: A contract generally giving the buyer the right, but not the obligation, to sell at the strike price. Assignment: The requirement for an option seller to fulfill the contract after the holder exercises.
Contract terms can change the practical result
American-style contracts permit exercise before expiration; European-style contracts restrict exercise to expiration. Physical versus cash settlement, the settlement reference, multiplier and broker cutoffs must be checked. Expiration payoff is not the option's mark-to-market value before expiration. Exercising a physically settled long option can create a stock position with risks beyond the premium originally paid.
Try it with a hypothetical example
Read an option’s specifications and OCC risk disclosure. Record right, strike, expiry, multiplier, exercise style, settlement and total paid premium.
A question to think through
A physically settled call finishes in the money. Does the premium alone describe all exposure if exercise creates a share purchase?
Compare your reasoning
No. The option premium limits the loss on the unexercised long option, but exercise can create a funded or leveraged stock position. Check broker handling and account resources.
A moment to reflect · optional
At expiration, what is the net result for the $100-strike call bought for $5 if the stock is $103?
Think through your answer, then compare it with the explanation.
Reveal the explanation
A $2-per-share loss, or $200 on one standard 100-share contract, before other costs.
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Sources & editorial notes
Reviewed 2026-10-13 · My Market Book editorial team. Examples are hypothetical unless identified as historical. General education, not a personal investment recommendation. Next scheduled review: 2027-04-11, or earlier after a material change. Conceptual and evergreen.