如果花$5买的call， 如果这个股票第二天从$50涨到$60，那么你的call就(差不多)值$5+$10=$15。 转手卖掉，就净赚$10, 200% profit.
当然钱不是那么好赚的，弄不好，会血本无归。
https://www.nerdwallet.com/article/investing/call-options
An example of buying a call option
XYZ stock is trading for $50 a share. Calls with a strike price of $50 are available for a $5 premium and expire in six months. In total, one call contract costs $500 ($5 premium x 100 shares).
The graph below shows the buyer’s profit or payoff on the call with the stock at various prices.
Because one contract represents 100 shares, for every $1 increase in the stock price above the strike price, the total value of the option increases by $100.
The breakeven point — above which the option starts to earn money, have intrinsic value or be in the money — is $55 per share. That’s the strike price of $50 plus the $5 cost of the call. When the stock trades between $50 and $55, the buyer would recoup some of the initial investment, but the option does not show a net profit.
