Shares of technology companies tumbled as traders rotated out of the leading stock-market sector due to valuation concerns.

SpaceX is now bigger than Amazon. Its shares are more popular than every other stock on the market, combined. And it just bought an AI company for $60 billion.

In a striking twist of the markets, SpaceX shares have rocketed up by over 14 percent this Tuesday, propelling the company's valuation beyond that of Microsoft and landing it in…