The market value of the S&P 500 index at its peak on February 19 was $52.06 trillion, according to CNBC on March 14, citing data from FactSet, a site that tracks US stock market activity.

At the close of trading on March 13, the S&P 500, a gauge of the health of the US economy, had plummeted to $46.78 trillion, down more than 10% from February 19, or about $5.28 trillion in three weeks.

The sharp decline in the S&P 500 index came as US President Donald Trump opened a trade war by imposing tariffs and reciprocal duties on some of the country's major trading partners.

Observers have also noted signs of slowing economic growth, from consumer sentiment surveys to the bleak business outlook for retail giants like Walmart.

"While many believe that it is too early to talk about a recession, there is widespread concern about the new administration's erratic policies," CNBC quoted strategist Emmanuel Cau of Barlays as saying on March 14.

Another factor contributing to the stock market’s worrisome performance comes from developments in artificial intelligence. Since November 19, 2024, Nvidia shares have fallen 17% in value, and MAGS (an exchange-traded fund that holds seven major U.S. tech names) has fallen 19%.

The fact that AI-related stocks hit record highs before plummeting as much as 10% over the past three weeks has led to concerns that the stock market is overvalued, with some stocks reaching market capitalizations of more than $3 trillion at one point.