Big Tech performance raises questions over whether stock markets are overheating

Yet, there are signs that the strength has not turned into a speculative frenzy

The so-called Magnificent Seven, which include Apple, drove the market’s gains.

US stocks’ torrid climb to start 2024 is evoking worrisome comparisons with past boom-and-bust cycles on Wall Street, sparking debate over the risk that the market is overheating.

There is ample reason to wonder whether shares have advanced at an unsustainable pace: The S&P 500 Index has closed at record highs 16 times this year, accounting for about a third of all trading days; artificial intelligence darling Nvidia has soared nearly 80%, adding roughly $1trn in market value, even after sliding Friday along with other tech shares; and speculative areas such as Bitcoin have surged.