Venture capitalists invested $4.5 billion in biotechnology firms in 2013, an increase of 8% compared with 2012, according to a report from PricewaterhouseCoopers and the National Venture Capital Association. The number of investments made, however, dipped by 2% year-over-year. The biotechnology industry attracted the second-largest amount of funding after the software industry. Investor optimism was fueled by a strong exit market, an improved economy, and the involvement of corporations in deals, NVCA President Bobby Franklin says. In contrast, investments in the medical device industry fell 17% to $2.1 billion in 2013. The cleantech sector saw a precipitous 54% year-over-year drop in venture backing in 2013 to $1.5 billion. The high-water mark for cleantech venture backing was 2011, when the sector raised $4.4 billion.