The tragedy in Brazil brings back memories of the investment opportunities that existed due to the Deepwater Horizon oil spill.
Brazil markets were closed when the dam broke, ADRs took a significant hit (my guess is that’s there’s more downside today as the death toll is rising, along with criticism of such a disaster happening less than 5 years after a similar one (previous one being much larger in volume, but lower death toll).
In any event, in situations like these I think the stock is way too risky, as governments might end up forcing a breakup of companies involved in environmental disasters. However there might be good opportunities in trading the bonds, as there’s definitely underlying value to the company.
Back in the Deepwater Horizon days there was some nice money to be made trading or investing in BP bonds (they were selling at about an 8% yield at a time of very low yields everywhere IIRC). I regretted not going into that trade with a more substantial investment.
I haven’t looked into VALE bonds yet, but I would guess that they might not have the same market as BP bonds.