There's been a massive change to public markets in the last decade and the retail path to making money seems to have closed. I made a some money on IPOs using a laughably simple heuristic:

"Is the company market cap low? Do they have a decent product? Is it plausible they'll 10x? Yes -> Buy some amount I can afford loosing"

For example, Tesla IPO'd at $5B cap, it was perfectly plausible to believe they'd be worth $50B some day. Shopify IPO'd at $1.3B, Square at $3B, 10x was perfectly believable. Uber IPO'd at $75B, I did not believe they'd be worth $750B any time soon, or ever. Do I believe SpaceX will be worth 20T in like 10 years? Lol. Fmao even.

Today's IPOs at $1T+ means that private money figured this out and cut the retail public out, IPOs seems to be a really terrible deal these days.