Berkshire Hathaway stock has underperformed the S&P 500 Index by 16.3% year-to-date.

In stark contrast, Berkshire Hathaway's stock price remained largely flat during the month. As a result, Berkshire’s widely held Class B shares have lagged the S&P 500 Index by 16.3 percentage points year-to-date, the largest gap so far this year. At the end of March, Berkshire Hathaway stock was only barely ahead of the S&P 500 by 1.8 percentage points. Since then, the S&P 500 Index has surged by more than 35% in April and May, while Berkshire Hathaway's stock price has fallen by nearly 11%. Chart analysis from 22V Research shows that Berkshire Hathaway’s relative performance against the S&P 500 Index has dropped to its lowest level since 2007.