Buying an option (a call if you're bullish or a put if you're bearish) gives you the , but not the obligation, to trade a stock at a fixed price.
Selling an option (also called "writing") means you take on the to trade if the buyer chooses to exercise their right. selling options vs buying options
: Theoretically unlimited for call buyers, as there’s no ceiling on how high a stock price can go. Buying an option (a call if you're bullish
Buying vs. Selling Options: Which Is Riskier? - Investopedia but not the obligation