Playing to strengths
Buy low; sell high
Two things, very simple; makes sense. In 40 years in finance I rarely found people who were consistently good at both. The industry has a natural bent to invest rather than divest. In early years as an analyst, people asked me what to buy; few asked what to sell.
Some were better at shorting, ie selling, but not always good at covering the short, ie buying. When natural buyers or natural sellers had to do the opposite of their strength, it was often too early or too late.