National Discount Brokers

(NDB)

jumped 87.1% in early trading after

Deutsche Bank

offered to buy the 84% it doesn't already control for $1 billion. That's $49 a share, nearly twice Monday's closing price of $25.25. NDB said it also had received offers from other companies. The news pushed other online brokers higher.

E-Trade

(EGRP)

was up 6.7%,

Ameritrade

(AMTD) - Get Report

was up 6.2%, and

Charles Schwab

(SCH)

rose 4.1%.

Nasdaq

market maker

Knight Trading

(NITE)

was up 12.2%.