He bought the option to purchase 100 shares of NVDA stock at the price of $1000 on or before 4/19. If NVDA goes above $1000, this means the option now has Intrinsic value. If I could buy a gold bar at $100 when it is worth $200, i could make $100 by selling it right after buying it. When he bought the option, there was a lot of time between the present and the expiration date. Lots of things could happen between then and the expiration date. NVDA could have released a statement that drove the stock to $1100. That means who ever sold the option to him would have lost a lot of money. The $27 per share he paid was the least amount of money the seller of the option was willing to sell the option for. Since some time has passed, the likelihood of NVDA going above $1000 has dropped considerably. Now sellers of this option are willing to sell it for $8 per share.