Technology

unfortunately you can't really get rich from knowing a bubble will happen. things like shorting, put options, bear certificates, and etfs with inverse leverage either have terrible risk reward ratios (you can basically lose infinite money from shorting, that's what the whole gamestop/amc thing was about) or very bad long-term gains (bear certificates and inverse etfs usually only track day-to-day changes and generally fall in value when the stock they're tracking fluctuates in price).
of course, if you know when the crash is gonna happen, it's a completely different story. then you can buy shorts/puts/etc just before the bubble bursts and laugh yourself to the bank (assuming the firms on the wrong end of those assets haven't gone bankrupt, which is also a very real risk in a situation like this)

The challenge, as always, is to never underestimate a bubble's capacity to outlast your solvency. I personally know people who have been heading against the housing "bubble" in Canada bursting since 1999. They've spent a lot of money with nothing to show for it, yet, and missed out on housing prices, like, quadrupling? Quintupling?

So, good luck. Buying out-of-market puts might be a safer bet, since you're most likely to "just" lose all your money, with a small chance of a massive payout of it "properly" crashes.