What just happened? Morgan Stanley on Thursday announced intentions to purchase online trading platform E-Trade. The all-stock deal is valued at roughly $13 billion and represents the largest takeover of an American lender since the global financial crisis in 2008.

With the acquisition, Morgan Stanley will take on more than 5.2 million additional customer accounts and some $360 billion in assets. They'll join Morgan Stanley's existing three million clients and their $2.7 trillion in assets.

E-Trade stockholders will receive 1.0432 Morgan Stanley shares for each E-Trade share they own, or $58.74 per. That's a more than 30 percent premium over the closing price of E-Trade shares on Wednesday.

As The New York Times correctly highlights, traditional corporate finance heavyweights like Morgan Stanley are increasingly looking to cater to customers that have smaller net worth. Similarly, online brokers that once hoped to overthrow conventional trading houses are struggling to cope with declining profits resulting from lower interest rates, falling commissions and digital "robo-advisors."

James Gorman, Chairman and CEO of Morgan Stanley, said E-Trade CEO Mike Pizzi will be joining the company to continue to run the E-Trade business and lead the integration effort. Pizzi will report directly to Gorman and will be joining Morgan Stanley's Operating and Management Committees. What's more, another (unnamed) E-Trade executive will be joining Morgan Stanley's board.

Morgan Stanley expects the deal to close in the fourth quarter of 2020, pending customary regulatory approvals.

Masthead credit: E-Trade by Sundry Photography. Day trader by GaudiLab.