The stock of Chicago Bridge and Iron (NYSE:CBI) is up 71% this year compared to a 27% return for the S&P 500. Looking at the long term, shareholders have drastically outperformed the market over the past five years with a 708% return compared to 120% for the S&P 500. So just what caused this incredible run and is it about to run out of steam?

A natural gas-powered rally for the ages
Since 2010, the company has seen exceptionally high demand for its products and services with revenues growing 25% in 2011, 21% in 2012, and 85% over the last 12 months. These gains have been driven by demand for natural gas projects across the world and further boosted by the acquisition of Shaw. The future for Chicago Bridge and Iron investors is largely tied to continued demand for energy, but how can investors make sure this demand is sustainable?

In the video below Motley Fool analyst Blake Bos goes over the cause of Chicago Bridge and Iron's recent rally, and gives investors the key areas they'll need to watch to make sure this rally can continue.