Elon Musk wants his two largest companies under one roof, and he wants it fast.

Space Exploration Technologies Corp. (NASDAQ: SPCX) and Tesla Inc. (NASDAQ: TSLA) are moving toward what would be the largest corporate merger in history, with an announcement possible as early as December, Bloomberg News reported Thursday, citing people familiar with the talks.

According to the report, Musk is pushing for a deal that could land around Tesla's Dec. 3 annual shareholder meeting, though the timing could slip into early 2027.

Tesla shares rose 2% to $398.75 on Thursday afternoon, a fifth straight gain. The stock is up 16% since the Nov. 5 close, its best five-session run since September 2025, adding about $218 billion in market value.

At current prices, the two companies are worth about $3.5 trillion combined. Special board committees are negotiating the structure, governance and share-exchange terms, Bloomberg reported.

The State Street Consumer Discretionary Select Sector SPDR ETF (NYSE: XLY), where Tesla is among the top holdings, slipped 0.4% on Thursday.

Chart: Tesla's Five-Day Gain Is Its Biggest Since September 2025