A conversation with a fellow investor some time back got me thinking. The investor had placed a buy order for a United States (U.S.) listed counter shortly after the market opened, only to find that the price filled was higher than what was expected based on the previous session's closing price. There was no major news overnight, nor had the company announced anything significant. Naturally, the investor wondered what had happened. As it turns out, this is not an uncommon phenomenon in the U.S. markets. Picture generated by ChatGPT If one were to observe the volatility of U.S. equities throughout a typical trading day, a pattern tends to emerge. Volatility is usually the highest during the opening period, gradually declines as the day progresses, and then picks up again near the market close. When plotted on a chart, the shape looks like the letter "U", hence the term "U-shaped trading day"....