Once again, President Donald Trump affected the stock market mood, by confirming that import tariffs on Canada, China, and Mexico will be introduced next week.
This came a day after the announcement of tariffs on goods from the EU.
Since the targeted countries have threatened countermeasures, the market's fear of a full-scale trade war is increasing – and with it, the fear of rising inflation in the US.
Another uncertainty is what a consumer price index to be released on Friday will show.
It is the indicator that the central bank, the Federal Reserve, relies most heavily on in assessing the US inflation level – and thus the timeline for a potential interest rate cut.
"Waiting for clarity"
The overall uncertainty surrounding both the starting points and the rules going forward is increasing investors' tendency towards cautious restraint.
We are in a stalled, range-bound, somewhat irrational market while we wait for clarity, says Jay Hatfield, CEO of the financial analysis firm LLC, to CNBC.
The Dow Jones industrial index fell 0.4 percent on Thursday, the broad S&P 500 index 1.6 percent, and the tech-heavy Nasdaq composite index 2.8 percent.
The fear of inflation also increased slightly due to American GDP statistics on Thursday, which showed that the price increase rate in the US was slightly higher than feared.
The American semiconductor giant Nvidia, the world's second-highest valued listed company, released its quarterly report after the market closed on Wednesday – and exceeded analysts' expectations for both actual results and future prospects.
"Extremely nervous stock market"
Still, the company's share fell 8.5 percent in Thursday's trading.
Nvidia's revenues were outstanding, but they come in an extremely nervous stock market, says James Demmert, investment manager at the advisory firm Main Street Research.
In addition to all this, those who worry about the US's hitherto strong labor market also got something to worry about.
The Labor Department released figures showing that new applications for unemployment benefits increased by 22,000 to 242,000 last week.
That was 24,000 more new applications than analysts had expected.
In an index that runs over four weeks, to compensate for random changes, the number of new applications landed at 224,000, an increase of 8,500.
