Optimism among middle market companies is increasing, with revenue, hiring, confidence, and investment all on the rise. The gains among this group could prove to be an indicator that the rest of the economy will rebound. The middle market serves as a critical engine for the U.S. economy, accounting for approximately one-third of non-government GDP and more than one-of-three domestic jobs. Middle market revenue increases of 5.8% for the first half of 2013, and expectations for increases greater than 5% for the next 12 months, far outpace the 1.2% revenue growth estimate for the S&P 500 Stock Index. However, challenges still persist for the middle market. Questions around healthcare legislation's impact on business, the ability to maintain margins and the uncertainty of how government actions will impact business all remain challenges to companies in the middle market.