Here’s something I’d never seen done before – an analysis of Warren Buffett’s risk adjusted returns. Insider Monkey has run an interesting analysis on the Buffett portfolio calculating his alpha since 1977. The conclusion – as Buffett has aged and grown in size his returns have become substantially worse on a risk adjusted basis:
“Warren Buffett had a phenomenal annual alpha of 19% between 1956 and 1968. Our current analysis shows that his alpha was more than 30% between 1977 and 1981. During the 80′s and 90′s, his annual alpha declined but was still better than 12%. For the ten years leading to mid-2003, his annual alpha stayed around 12% per year. Since then, it started a steep decline; by the end of 2004 it was (still a respectable) 6% per year. Between 2005 and 2008 Buffett’s alpha averaged only 3% per year. Finally, in the ten years ending in 2009, it went virtually to zero. (For regression results and Buffett’s style drift, visit Insider Monkey)”
Is Warren Buffett another casualty of the tough investment environment? Looks like we can chalk this up under the “many myths of Warren Buffett” file.
Source: Insider Monkey