The S&P 500 index was up 28.5 percent, through Monday, its best performance since 2013

Posted on December 31, 2019

Broad indexes of the American bond markets are up nearly 9 percent. Gold jumped 18.5 percent and silver nearly 16 percent, and other commodities were also up. (Futures prices for hogs, in case that had been your pick, gained about 18 percent.)

It was a remarkable across-the-board rally of a scale not seen in nearly a decade. The cause? Mostly a head-spinning reversal by the Federal Reserve, which went from planning to raise interest rates to cutting them and pumping fresh money into the financial markets.