I know several people that got cleaned out in IPOs partially due to how taxes work on no-liquidity (lockout) periods. If you IPO'd at $10 ($3 goes to the tax man), and when you can finally sell it 6mo later and stock is only worth about $3, the IRS makes more money than you.

Checkout what happened at Uber [0].

My cousin at Aurora borrowed money for his tax bill on IPO. I don't know the final numbers, but I hope he at least broke even.

Real examples include: $GRAB, $AUR, $UBER

[0] - https://www.cnbc.com/2020/08/28/nearly-200-uber-employees-su...