Charles Schwab (SCHW) is in talks to buy TD Ameritrade (AMTD) and a deal could be announced as early as today, a source told CNBC’s Becky Quick. Shares of TD Ameritrade are up 26%, or $10.62, to $52.00 in premarket trading following the report. Charles Schwab is down 2% to $43.74 while peer E-Trade Financial (ETFC) is down 16c to $45.70.