Weeks of worry—about trade, growth, and Europe—knocked markets down. But today we have the reversal. Mario Draghi, the head of the European Central Bank (ECB), has once again come out in favor of looser monetary policy and lower rates, which cheered markets globally. And this morning, President Trump tweeted that he would be meeting with China’s leader, which further cheered markets. As I write this, the S&P 500 is up by 1 percent and well over 2,900. This level takes us to within 1 percent of a new all-time high.