Nitpick: you can’t lose over 100% of your investment using a put option. You can only lose the premium.
> Not with options.
you maybe meant to say "not when you buy options":
> 2. Sell a Call. This gives someone the right to buy the stock at a certain price (and you promise to sell at that price). If the stock is below that price your profit is what you sold the call. Your maximum loss is infinite since a stock price has no (theoretical) limit.
the entire point of everything under discussion here is that "betting against a stock" can take multiple forms. if you'd like to pick one, google, or your interlocuters, could tell you what the maximum possible risk is.
keeping your money in cash is a form of betting against a whole lot of stocks simultaneously.