Sharp swings in U.S. stocks are increasingly being tied to the words and online posts of Donald Trump, with traders reacting quickly to signals on policy, conflict, and negotiations.

Market data show that several of the biggest gains and losses in the S&P 500 over the past year have followed Trump’s public remarks, underscoring his outsized influence on investor sentiment.

Recent volatility tied to tensions involving Iran highlighted this pattern. The benchmark index dropped sharply after Trump signaled reluctance toward a ceasefire, only to rebound days later when he suggested negotiations were progressing.

Analysts say the pattern has conditioned investors to respond quickly to shifting rhetoric. “Investors have been conditioned, not wrongly, to expect that if things get too bad… they’re waiting for the tweet that says, actually, we’re good,” said Baird Investment Strategist Ross Mayfield.

The influence extends beyond equities, with oil prices and other commodities also reacting to developments tied to geopolitical signals from Washington.

For market watchers, the trend reflects a shift where daily commentary, rather than traditional economic indicators, is driving short-term direction.

“I have never seen a market that’s been this moved by chatter coming out of the White House on a daily basis,” said Ed Yardeni, President of Yardeni Research, Inc.