Due to tax cuts overseas profits flooding back to the US
Clear principles of economics made this an easy call prior to the tax cuts.
The numbers are staggering. US business had ~$2.6T parked offshore to avoid what was one of the highest corporate tax rates in the world. Trump's tax bill cut corporate taxes enough that US corporations are set to bring ~50% of that to the US this year. That means more jobs, a stronger economy, and better dividends. That compares to US companies bringing money parked offshore last year at $35B.
The BEA's analysts explain why this happened: "The large magnitudes (of inward capital flows) ... reflect the repatriation of accumulated earnings by foreign affiliates of U.S. multinational enterprises and their parent companies in the United States in response to the 2017 Tax Cuts and Jobs Act."
It's a shot in the arm for the U.S. economy.
Of course, you say. It's entirely logical to suppose that by slashing the top corporate tax rate from 35% to 21% — a 40% reduction — and by giving one-time breaks to those companies that had piles of cash sitting overseas, money would flow back into the U.S. After all, Trump's 21% tax rate is now lower than the current OECD average corporate tax rate of 25%.