I thought it tumbled (5%) when the markets opened Monday because his talk about a 3rd party reduced investor confidence in him minding the store.
What does his feud with Trump have to do with it? They've been feuding a couple months. It's only down 0.8% since May 9.
It's down 5% THIS WEEK. IOW, it was going up during the feud.
The emphasis on the "feud" makes no sense.

Don't know why Jalopnik focused on the feud.

Investors are nervous about the stock's overvaluation being at risk because the cult leader doesn't have his eye on tye ball.

If not, what do you think it is for?

I think that's a tantrum against the system.
And, that's not why investors are nervous.
If the feud made investors nervous, the stock wouldn't have gone up for 6 weeks after he was leaving DOGE.

He's out for himself, and he sees his government subsidies threatened by Trump's bill. The point is that the feud has gone up to another level with Musk talking about a rival party. The stock price could creep up while they thought Musk was just pumping out the occasional tweet against Trump; now they think he wants to get serious against Republicans (by a party seems unlikely to me; funding Musk's own nutters in Republican primaries seems more feasible).

If it's a tantrum, it's a tantrum against Trump, not against "the system".

How is accusing someone of throwing a tantrum giving credit?

That makes it sound like he's a rebel. He's taking revenge for Trump cutting his subsidies. It's self-interest, not rebellion.

Tesla is overpriced by a power of 10. It's PE is over 190, when most auto makers are around 10. $20 would be a more appropriate price for this company than $300.
Buyers keep falling for the tech advances Musk keeps promising, but never delivers.
Sales are plummeting in Europe, no growth here, and the Cybertruck probably has a year, 2 at the max before it goes the way of the Edsel.

They "RALE"?