I don't see any plausible explanation, I believe current valuation is absolutely insane. I am a big fan of Tesla and it was actually the first stock I bought. The only reasons I haven't sold is because I'm afraid of the tax consequences and since it seems to defy logic, it may very likely keep going up. I wouldn't be surprised now if it hit a $1t market cap
Regarding tax consequences in specific - you are able to donate appreciated stock to charity, and both you and the charity will not pay tax on the gains. Can be great for situations like this. You'd get a receipt for the current value.
Not sure the exact process, but if it's something that you can look into further if you may be interested.
And, if you want to keep the position, you can re-buy in, thus raising your cost basis in the stock (significantly).