I had a small position in this Argentinian utility company (Metrogas, MGS) when it suddenly declared bankruptcy. That was about 10 years ago. I still had that position with a $0 value on my account until last year. Then all of a sudden, the position was closed and I got paid $10k from some corporate action. That was the only explanation on the brokerage statement. Obviously, I didn't call to clarify :) But I am still curious what might have happened.