This happened to me with Tesla. I bought a hundred shares at $35, and had a sell order that said, "sell if it drops more than 10%." Two months later, around $80, it fell to $70 or something like that, and mine automatically got sold. Then it jumped to $250.

But I was gambling with it (it's the only time in my life I've bought a single company's stock like that), and I think in retrospect the result is quite good. I just can't shake away the "if only..." feeling. :-)