Goldman Sachs chief U.S. equity strategist David Kostin uncovered an important change in market performance in 2023, one that will have investors focusing on individual company news rather than macroeconomic factors. In his most recent Weekly kickstart report, Mr. Kostin noted that in 2022, macroeconomic factors like money supply growth, interest rates and gross domestic product growth explained 69 per cent of equity returns. For example, rising rates hurt auto manufacturers (the worst performing S&P 500 sector), tightening money supply hit U.S. bank stocks, and oil companies benefited from strong nominal GDP growth. In 2023, this trend has reversed with...