Hedge fund firm D.E. Shaw & Co. laid off 150 people today, according to sources familiar with the situation.

The cuts, which amount to around 10 percent of the New York–based alternative asset manager’s work force, were across the board and included partners and portfolio managers, these sources confirmed.

The decision to reduce head count came about as a direct result of the D.E. Shaw’s diminished asset size, stemming from redemptions that began in 2008. (The firm’s flagship multistrategy fund was down that year 8 to 9 percent, depending on the share class.) D.E. Shaw’s assets have fallen from more than $30 billion in 2008 to $21 billion today. “The D. E. Shaw group has taken steps to strengthen our business and maximize value for our investors over the long-term,” says a spokesperson for the firm.