The Toronto-Dominion Bank (TSX:TD), the Canadian bank that's been expanding through acquisitions, is weighing a deal for the brokerage firm Cowen Inc. (NasdaqGS:COWN), according to people familiar with the matter. The Toronto-based lender is working with advisers to study a possible transaction for Cowen, said the people, who asked not to be identified because the matter isn't public. No final decision has been made and Toronto-Dominion could opt against pursuing a deal, the people said.