Mark Hulbert: Big Tech stocks are the market’s superstars but rising rates could bring them down

Higher U.S. interest rates threaten the so-called FAAMG stocks. I’m referring to Facebook FB, Apple AAPL, Amazon.com AMZN, Microsoft MSFT and Google (Alphabet) GOOGL, whose combined market caps now represent a quarter of the S&P 500’s SPX total. The source of this growth in valuation has been largely a mystery — until now.

Recent research shows that declining interest rates are helping to fuel these companies’ higher valuation. Rising rates, therefore, could cause these mega-cap stocks to lose market value.

This…