Secondary Market – Is it profitable?

I've been researching a bit into the secondary market, I know “Hiive” exists but the minimum purchase is 25k for shares so I can't use it.

My question is: Is the secondary market profitable? Like if you can get your hands on shares of a company before it goes public does the news going public skyrocket the stock?

I would assume for example: If you can get your hands on apple before it went public and hold on to it you would make millions.

I'm eying OpenAI but I don't want to fork over 25k nor know how to get like 10-100shares. I just want to invest like $100-$1000. Anyone know if this is possible?