As the economy appears to be weakening and the S&P 500 is at an all-time high, it is useful to see how the different sectors within the index have performed since the last downturn. This becomes even more relevant when considering that the S&P 500 appears to be overvalued compared to the real economy, as I've already explored in another analysis . Historically, the best performing sectors will be the ones to suffer the most: Technology in 2002 and Real Estate and Financials in 2008. As usual, there will be a myriad of fundamental factors that investors will try to use to justify why those sectors have performed so well. This does not change the fact that, because of the mathematical realities of how we measure financial metrics, everything will tend to mean revert in the long run. Sector performance Using data from S&P, it is possible to see how the different sectors have performed since 2009. It is easy to see how two sectors have outshone all others...