Oh its risky for sure. But, (and I hope your friend isn't in this boat) the real danger is if you are trading most or all of your position.

I have a core position that I'm not touching. Regarding CYDY in particular, if there is a short attack, or something that causes me to become a buyer, its new money in. Then I sell for a profit when fear subsides and reason returns.

I figure worst case scenario I hold those shares long term.

At the end of the day its akin to gambling. Certainly dont recommend it to everyone.