Investors not betting against the market rally by Laura Lorenzetti @FortuneMagazine July 9, 2014, 8:20 AM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons Investors appear to be more optimistic than ever that the recent stock market rally will continue. Short selling, or bets that the value of stocks is about to fall, is at its lowest level since before the financial crisis, even as the market hits all-time highs. The proportion of shares borrowed by short sellers has dropped to about 2% of all U.S. S&P 500 shares, close to the lowest level since 2006, according to Markit data reported by The Financial Times. The UK and Europe have also recorded very low levels of short interest recently, the newspaper notes. The drop in short selling indicates that many investors and hedge funds are not ready to bet against a booming market. Both the Dow Jones industrial average and the S&P 500 index have hit all time highs in the last month. The Dow hit a record high of 17,068.26 on July 3rd, a 136% gain over its post-financial crisis low in March 2009. The S&P 500 recorded an all-time high on the same day. It hit 1,985.44, a 191% gain over its recession low in March 2009. However, other high-profile money managers, such as Greenlight Capital’s David Einhorn, have warned that market euphoria has taken over and warn of bubbles in certain asset classes, such as U.S. technology shares. Short interest in 2007, right before the collapse of Lehman Brothers and the resulting financial crisis, was at a high of about 5.5%, according to Markit data. As the market gains increased over the last year, buoyed by infusions of cash from the Federal Reserve’s quantitative easing policies, hedge fund managers were squeezed by short selling bets and opted to cut those holdings, the FT explained.