LONDON –

Investor unease about an increasingly uncertain environment is rising, as Norway's shock rate cut on Thursday highlights how U.S. tariffs, Middle East conflict and a shaky dollar make global monetary policy and inflation even harder to predict.

Norway's krone slid roughly 1% against the dollar and the euro in a sign of how unexpected the move was. And Switzerland, which cut borrowing costs to 0% on Thursday, confounded some expectations among traders for a return to negative rates in the deflation-hit nation, as its central bank warned of a cloudy global outlook.

Just a day earlier, the U.S. Federal Reserve kept rates on hold, and chair Jerome Powell said "no one" had conviction on the rate path ahead.