Stock option refers to the right to buy or sell a certain underlying contract, which is valid for a certain period of time. The buyer of option is called the buyer of option and the seller of option. Similarly, the buyer of option is called the buyer of option, and the seller of option is called the seller of option.

For the buyer of "call option", he can buy shares at the agreed price within a certain period of time without actually buying. If the agreed price is higher than the market price when the option expires, he can choose to exercise, that is, buy the stock at the agreed price and sell it at a higher price in the market, thus obtaining the difference income; If the agreed price is lower than the market price, you can choose to give up the option to avoid losses. The biggest loss for the buyer is royalties.

For the buyer of "put option", he can sell the stock at the agreed price within a certain period of time without actually selling it. If the agreed price is lower than the market price when the option expires, he can choose to exercise, that is, sell the stock at the agreed price and buy it at a lower price in the market, thus obtaining the difference income; If the agreed price is higher than the market price, you can choose to give up the option to avoid losses. The biggest loss for the buyer is royalties.

For the seller, if the option is exercised, he must buy or sell the stock at the agreed price. No matter how the market price changes, he may face potential loss risks. So the seller will charge a certain royalty as compensation for taking this risk.

The trading of stock options needs to be carried out in a specific exchange in the securities market, and investors can register to open an account for trading through the securities account or warehouse sharing system. Before trading stock options, investors need to understand the rules and risks of options trading, and make reasonable investment plans and risk management strategies according to their investment objectives and risk tolerance.