Summary
- An analysis found U.S. stock-market volatility is increasingly being driven by President Donald Trump’s remarks and social-media posts.
- Since Trump took office, the five biggest up days and five biggest down days in the S&P 500 index have all been tied to his remarks on tariffs, a trade truce and Iran, with the impact spreading beyond stocks to commodities and oil prices.
- On Wall Street, some say presidential remarks now drive market direction in place of economic data, interest rates and corporate earnings, while others argue structural factors such as the VIX and the expansion of passive investing have also played a role.
Forecast Trend Report by Period
President Donald Trump’s remarks and social-media posts have emerged as a key driver of volatility in U.S. stocks, an analysis found.
Bloomberg reported on April 25, citing Fundstrat Research, that since Trump took office, the S&P 500’s five biggest up days and five biggest down days have all been linked to his comments or posts. Fundstrat said that was unusual, with no political leader since the Reagan administration in 1981 so frequently driving sharp market swings.
The market reaction has been immediate. The S&P 500 jumped 9.5% on April 9, 2025, when Trump announced a pause in tariffs. It rose 3.3% on May 12 after the U.S. and China agreed to a trade truce. The index fell 4.8% on April 3 after broad tariff measures were announced, then slid another 6% the next day after China imposed retaliatory tariffs.
The same pattern played out during the Iran war phase. The S&P 500 fell 1.5% immediately after Trump said on March 20 that he did not want a ceasefire. It then rebounded 2.9% after his March 31 remarks that negotiations were making progress and the war was nearing an end. More recently, the index traced a sharp V-shaped move, dropping 9% from its previous high, rebounding within 11 trading sessions and then setting a fresh record.
The impact did not stop at equities. It spread across financial markets, including bigger swings in commodity prices and oil volatility that approached levels seen at the start of the Covid-19 pandemic.
On Wall Street, some see the president’s personal influence as expanding. Economic data, interest rates and corporate earnings used to be the main market drivers. Now his remarks themselves are moving markets. Fundstrat described the president as effectively holding the market “on a leash.”
There is also a counterargument. The Cboe Volatility Index, or VIX, has averaged 19.3, not far from historical norms. Structural factors, including the rise of passive investing and greater sensitivity to news, may also be contributing.
Lee Song-ryeol, Hankyung.com reporter yisr0203@hankyung.com
Korea Economic Daily
hankyung@bloomingbit.ioThe Korea Economic Daily Global is a digital media where latest news on Korean companies, industries, and financial markets.
