Key Facts

—The probe. Brazil’s consumer watchdog, Senacon, opened an investigation on June 29 into three lenders charging abusive interest.

—The rates. Valor S/A charged 21.72% a month, or 957.7% a year; Cobuccio 956.6%; Crefisa 871.4%.

—The math. A 1,000-real ($193) debt at twenty percent a month swells past 9,500 reais ($1,834) within a year.

—The product. All three rates were on unsecured personal loans, the costliest mainstream credit in Brazil.