The dollar is strengthening because markets around the world are not actually in a synchronized global recovery as was previously thought. Instead they are diverging, and mostly to the downside. China is slowing, Europe is slowing, emerging markets are slowing. Investors looking for yield around the world move to US dollars, as there are still plenty of growth stocks in the US as well as rising yields in US treasuries. So the dollar strengthens, and will continue to strengthen, at least for a little while longer. Not forever, of course, but for the time being that seems to be what is happening. Why is oil still going up? Supply cannot keep up with demand. During the great oil glut that started in 2014/15, because oil prices crashed, exploration went way down. Now that the gut is cleared, oil has gone up again, as new supplies and infrastructure are not keeping up with demand, even while the dollar is rising.