The dollar typically strengthens in times of economic or geopolitical strife, but in 2026 much of the uncertainty and political turmoil is coming from inside the US – and President Donald Trump has given a thumbs-up to the resulting plunge in the greenback. The dollar has dropped 9% overall against a basket of world currencies over the last year, and in January fell to its weakest level since March 2022. And the downward pressures don’t appear to be going away.