The stock rocketed up today and the puts rose about 20% as well (which is crazy and counter-intuitive). So, I was entirely wrong and made money anyway. Once I realized I couldn't account for what was happening, was totally wrong on the direction, and being offered a token gain to get out, I got out.
Someone was bidding up $50 puts expiring in 3.5 weeks and buying contracts today, while the shares were in the mid-300s. That's insane implied volatility.
Because the higher you are, the closer you are to a crash. Peaks take time to build, but crashes can happen overnight (or premarket).
If you write a put, you're long the stock. To hedge yourself, you'll need to short it. To the extent that that is difficult right now, nobody will be willing to write puts. (Strictly speaking, the put is so out of the money right now, that one would not have to short much today. But as soon as the stock price falls and approaches the strike, the writer of the put would need to start shorting. "Hey, anyone got some shares I could borrow?")
On the other hand, if you want to take a negative view on the company, buying a put is sensible thing to do. That'll drive the price of the puts up.
This is called IV expansion.
You could lock in gains using puts, but when you go and price out doing so you'll see exactly how much the market values the risk in the position.