The downside of SPACs is that if they don't do a reverse merger they're unlikely to appreciate in value like a normal stock (or index), so you're basically gambling the opportunity cost against a chance of significant gain.
If a SPAC doesn't find a company to merge with you get your money back and some interest. If a SPAC finds a company, you have the choice to (1) stay invested in the SPAC and therefore the company or (2) refuse the merger and get your money back with interest.
Interestingly when you invest in a SPAC you actually get two things (1) the option to invest in the company they find, and (2) a warrant to buy even more stock. What's even more interesting is that you could actually sell this warrant while keeping the option to invest in the company the SPAC finds.
The edge is twofold. First, it's a way to pool funding using an exchange rather than getting some bank to underwrite an IPO. Second, many of the people who run SPACs are famous investors who have a track record of success and have greater information and access than most investors.
With so many coming out, just keep jumping to new SPACS as the LOI or DA is announced. Just wanted to share my experiences.
EDIT: Nikola and QuantumScape (NKLA/QS) are the big ones that got attention. Every SPAC is hoping to make a run like QS; 10$ went all the way up to 100$ at one point. NKLA was a scam, but brought a lot of attention