When the Brumadinho dam collapsed on January 25, shareholders of mining giant Vale caught a break: it was a public holiday in the city of São Paulo, meaning the domestic stock exchange was closed. Company shares crashed 8 percent on the New York Stock Exchange, but delayed losses until after the weekend. On Monday, the effects of the disaster came like a wrecking ball: Vale stock crashed 24 percent and the company lost BRL 70 billion in market value, an all-time record for companies traded in Brazil.
Ratings agency Fitch downgraded Vale’s investment...