I reached out to my co-founder but haven't heard anything from him.

I also asked around and heard through the grapevine that the startup was sold for less than liquidation preference. But I don't know how reliable this is.

I suppose my main hesitation in hiring a lawyer is that it would cost me a bunch of money, only to find out that the startup was sold for less than liquidation preference. If I did get a lawyer to send a "strongly worded letter", would the company be required to provide details about the acquisition? Given that my co-founder is not being cooperative, I suspect he wouldn't share anything that he isn't legally required to