Dell and EMC are in merger talks that could result in the largest tech merger in history, The Wall Street Journal reported late Wednesday.

Of course, the "largest in history" part comes with some caveats. Even if the rumor is true, it doesn't mean a deal will come together, and any deal might not result in Dell acquiring all of EMC.

But if it did, Dell would be picking up a company with a market capitalization of around $50 billion. By comparison, Avago is paying "only" $37 billion to acquire Broadcom.

Any Dell/EMC could probably be chalked up as the latest fallout caused by Elliott Management, the activist hedge fund that, among other things, pushed Riverbed into a sale to private equity.

Elliott has voiced a litany of complaints about EMC management and has suggested the EMC Federation be broken up. The Federation consists of EMC II (the storage-related business that evolved from the original EMC), Pivotal, RSA, and VMware, with the recently acquired Virtustream likely to be added.

EMC has put more outside directors on its board to appease Elliott, but the hedge fund wants more. One possibility that's been floated is the idea of VMware acquiring EMC in what's called a downstream merger, but VMware CEO Pat Gelsinger has shot down that idea.

A formal truce period between EMC and Elliott expired on Sept. 30, so it's possible Elliott could start making noise again soon. One WSJ source speculates that EMC's Oct. 21 earnings release will be the real deadline before Elliott pipes up.

EMC stock was up $2.28 (9%) at $28.24 in after-hours trading Wednesday.