If it's a large enough publicly traded company that it's on the options market, you can buy puts to protect you from loss. I would expect you could limit your losses to maybe 25% of the current trading price, depending on the company.
Here's an example using Google:
If I was given Google stock at my job today, it would be valued at $2,347.86, because that's what it's trading for. I wouldn't normally own Google stock, as it's too big a risk to own individual stocks.
I have no opinion on the movement of the stock, but I want to minimize my losses, so I buy a put that allows me to sell the stock after my holding period for close to it's current trading price. Today there is a June 17 2022 Put for $2350, with an ask price of $267.90.
The $267.90 cost of this put is the cost of your insurance against the price going down.
I buy $267.90 puts to cover my company-gifted stock today. If my stocks vest May 20, 2022, I can sell them between May 20, 2022 and June 17, 2022 for $2350 by exercising my options. If the stock is trading higher than $2350, I can sell them instead on the open market.
This is called a 'protective put' because it protects your stock position against loss. In this case, the protective put cost me 11.4% of the value of my company-gifted stocks. So the most you stand to lose is the 11% cost of the put it today's price doesn't move much.