You do realize that no investment can go down more than 100% right?? And you SELL calls against your long positions to hedge, you don’t buy themexample: X, Y or Z security up 200, 300, 400% last year (or any year), take some profits on highest-cost shares => free up cash to buy other stuff person wants to invest in, etc.
A, B or C security down few hundred % take some losses, balance losses against gains to manage overall tax impact.
Hedge - buying puts can help with stuff wayyyy up (SPY and QQQ 4Q21); buying calls can enable buys of stuff which may drop significantly to a price a person is inclined to buy