Suppose I buy 100 shares of $ABC for $10 (total cost for me is $1000) and then sell a call option for $1 with a strike price of (say) $50. The absolute worst case scenario is that the value of my *shares* goes to $0, in which case I've lost $999.
On the other hand, if the price shoots up to, say, $85, I'm still obligated to sell them at $50. Since I bought them at $10, I've still made $4001 profit, but I'm still dissatisfied because I would have made $7500 if I hadn't sold the call option.
What you're describing is what happens if I don't already own those shares and the price skyrockets. If the counterparty exercises their $50 option when the current price is $85, then yes, I'm obligated to buy the shares at market price and sell for a total loss of ($STRIKE_PRICE * 100) - $5000 - 1.
On the other hand, if the price shoots up to, say, $85, I'm still obligated to sell them at $50. Since I bought them at $10, I've still made $4001 profit, but I'm still dissatisfied because I would have made $7500 if I hadn't sold the call option.
What you're describing is what happens if I don't already own those shares and the price skyrockets. If the counterparty exercises their $50 option when the current price is $85, then yes, I'm obligated to buy the shares at market price and sell for a total loss of ($STRIKE_PRICE * 100) - $5000 - 1.