Sitting onstage in Washington’s Ronald Reagan Building in July, Lloyd C. Blankfein said () had stopped using its own money to make bets on the bank’s behalf.

“We shut off that activity,” the chief executive officer told more than 400 people at a lunch organized by the Economic Club of Washington, D.C.

That may come as a surprise to people working in a secretive Goldman Sachs group called Multi-Strategy Investing, or MSI. It wagers about $1 billion of the New York-based firm’s own funds on the stocks and bonds of companies, including a mortgage servicer and a cement producer, according to interviews with more than 20 people who worked for and with the group, some as recently as last year.