Ruth Gottesman, widow of David Gottesman, a former Berkshire Hathaway Inc. director and Warren Buffett's colleague, has donated $1 billion to the Albert Einstein College of Medicine. This donation, funded by a portfolio of Berkshire Hathaway stock left to her by her late husband, aims to provide free tuition for medical students. It's one of the largest charitable donations to a U.S. school and possibly the largest to a medical school ever. Berkshire Hathaway's shares have significantly outperformed the broader market over the past decades.