Some investors hold that as goes January, so goes the year. The performance so far—with the S&P 500 down 1.7% by Thursday’s close—doesn’t hold out great hope. But the first three trading days of the year offered a useful run-through of three of the ways that inflation and the economy affect your portfolio.

The year started the way the last one ended, with all the focus on the Fed and inflation, only in the opposite direction.