Elon Musk’s next move could be a SpaceX-Tesla merger big enough to challenge Nvidia Corp. (NASDAQ:NVDA) for the title of most valuable company on Earth.

Just three sessions into its IPO, SpaceX (NASDAQ:SPCX) has already surged nearly 50% to roughly $2.6 trillion, leaving Tesla Inc. (NASDAQ:TSLA) and its $1.5 trillion behind.

The wider that gap runs, the cheaper Tesla gets to absorb, and the more control Musk keeps over whatever emerges.

The Math On A $5 Trillion Giant

The case for a merger, laid out this week by Bloomberg columnist Liam Denning, is about control as much as size. Any deal would be all-stock, so SpaceX would absorb Tesla by issuing new SpaceX shares to Tesla’s holders.