Isn't it possible to set the short order at a max limit to cut your losses? (this shows how little I know about having a trading account)

This might help: https://www.investopedia.com/articles/active-trading/091813/...

The problem with stops is that you run the risk of the price gapping up or down and your stop getting filled at a much different price than expected.

I'm an experienced trader in the sense that I've had only bad experiences trading. Thinking a stop loss order would help I (and the order) failed to account for one of those flash crashes that happen for no obvious reason other than to trigger execution of stopped orders.

With leveraged products (like rolling turbos [1]), that risk is usually on the offering institution? I dabbled in those a few times when pretty sure (or full) of myself. There are no margin calls in turbos, you add leverage to your liking (x 2, x 5, x 10, ..) and you pay a hefty interest on your leverage (say 7%). Your exposure is exactly the price you bought for.

[1] https://en.wikipedia.org/wiki/Turbo_(finance)

Unfortunately I was long Kraft (the food co), completely unleveraged, and got taken out at a 15% loss thanks to a flash crash-induced stop loss. It taught me a lesson that only losing real money teaches.

Sell short and buy a corresponding (shares short / 100) number of call options at $420 strike (which, in theory, if Musk were telling the truth, should essentially be worthless but in practice will come with some amount of premium). That way you have a guaranteed exit at $420/share + option premium paid. You could reduce your option premium cost while slightly increasing your max loss if you went with $430 calls or whatever.

Why not just buy puts and simplify the trade?

That could work too; without seeing the numbers it's hard to say. For example you might have a higher chance of losing your money due to theta decay depending on how far out you're buying. And the premium on the puts is going to be substantially higher than on the defensive calls unless you go significantly OTM.

The only reliable way to limit losses would be using options.