Shares in athenahealth (ATHN) plummeted yesterday after well-known investor David Einhorn announced that he believed the company was badly overvalued and could "easily fall" 80% or more. Einhorn was clear about his appreciation for the company and its business model, but he also noted that he thought the stock had crossed into bubble territory. The market responded by slicing 14% off athenahealth's market cap. Of course, this begs the question of whether it's time to follow legendary investor Warren Buffett and "be greedy when others are fearful."

Michael Douglass and David Williamson discuss the athenahealth news in this segment from Tuesday's Market Checkup, lay out the business case for athenahealth, and consider why Einhorn could be wrong about this fast-growing health care IT company. Watch the video below for more on athenahealth and its opportunities moving forward.