The premium is the price of being wrong
An option caps your loss at the premium but that premium is a real, frequent loss. Know your break-even before buying. Find it on the options break-even calculator.
Options PnL has more moving parts
A spot position's PnL is one subtraction. An option's PnL before expiry depends on the underlying move, time passed, and what implied volatility did β three dials, and the last two usually work against buyers.
Concrete case: you buy a 1-week BTC call, and BTC rises 2% the next day. You can still be down β if IV dropped after an event resolved (the "IV crush"), the volatility repricing can outweigh your directional gain. Traders who buy options into announcements learn this expensively: right about direction, wrong about the vol, net loser.
At expiry it simplifies to intrinsic value: max(0, spot β strike) for calls, minus the premium you paid. Before expiry, time decay (theta) bleeds the position daily β a week-out at-the-money option can lose 2β4% of its value per day just standing still. Directional conviction with a deadline is what you're actually buying.
FAQ
How do I calculate options PnL?
For a call: max(0, price β strike) β premium. For a put: max(0, strike β price) β premium. The premium is your maximum loss if the option expires worthless; upside is (theoretically) unlimited for a call.
Why do most options expire worthless?
Because the price must move past the strike by more than the premium just to break even. Buying options is buying time and direction β pay too much premium and even a correct call loses.