If Sirius stock plummets to $1 after selling a cash-secured put with a $4.50 strike and receiving $0.32 premium (effective purchase price $4.18), the investor would be down $3.18 per share, or 76%.
"if Siri plummets to $1 you will be forced to buy Siri for 450 so yes you did get paid 32 cents for making this deal so your true purchase price is 418 but still the stock fell to $1 this means that you are down $318 which means that you're down 76%"