Goldman Sachs chief U.S. equity strategist David Kostin became the latest prominent strategist to predict a two-part year in 2023 – a difficult and volatile first six months when stock prices adjust lower for falling profit expectations, followed by a modest rally in the second half. Adding analytical depth to Goldman’s forecast, Mr. Kostin’s colleague, U.K.-based global strategist Peter Oppenheimer, outlined his argument as to why markets have yet to find a sustainable bottom and suggests ways to identify one when it happens. Mr. Oppenheimer believes that the speed of interest rate hikes is a major deterrent to equity buyers….