Morgan Stanley said on Thursday it would buy discount brokerage E*Trade Financial Corp in an all-stock deal worth about $13 billion, the biggest deal by a Wall Street bank since the financial crisis. The deal will help Morgan Stanley boost its wealth management unit, a business that Chief Executive Officer James Gorman has been trying to build out to insulate the bank from weak periods for trading and investment banking. Morgan Stanley will get E*Trade's more than 5.2 million client accounts and $360 billion of retail client assets as part of the deal.

The brokerage's CEO, Mike Pizzi, will continue to run the business following the merger. "E*Trade represents an extraordinary growth opportunity for our Wealth Management business and a leap forward in our Wealth Management strategy," Gorman said. E*Trade became popular nearly two decades ago by running commercials that blasted financial advisers for high fees. Its revenue growth has taken a hit in recent years from the emergence of digital upstarts called roboadvisers, falling commissions and lower interest rates. E*Trade shareholders will receive 1.0432 Morgan Stanley shares for each share as part of the deal.

That translates to $58.74 per share - a premium of 30.7% to the last closing price of E*Trade shares. Shares of E*Trade Financial were up 24.6% at $56 in the premarket trade. The deal is expected to close in the fourth quarter of 2020.