Subject: Re: SpaceX
Any guesses for what an ATM put will cost? In other words, how much of price fall just to break even.

Well, the numbers are in.
The stock price is about $204 at the moment.
The price of a January 2028 (longest dated) $205 put is around $65.

Not that bad, really. That would get you the right to sell at net $140 any time in the next year and a half, which is above the issue price of $135. I think it's fair to assume that most of the action in these first few days is short term exuberance that says little, good or bad, about the likely future trajectory.

If you're confident in your bearishness but short of cash, you could entirely fund that put purchase by selling a $230 call for the same price. That call sale trade, taken in isolation, doesn't lose money until the price sticks above $295, up another $90 from here. (about another $1.2 trillion in market cap)

Jim