Shares in athenahealth (NASDAQ: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.

Speaking of Warren Buffett, he just bought nearly 9 million shares of this company
Imagine a company that rents a very specific and valuable piece of machinery for $41,000... per hour (that's almost as much as the average American makes in a year!). And Warren Buffett is so confident in this company's can't-live-without-it business model, he just loaded up on 8.8 million shares. An exclusive, brand-new Motley Fool report details this company that already has over 50% market share. Just click HERE to discover more about this industry-leading stock... and join Buffett in his quest for a veritable landslide of profits!

David Williamson has no position in any stocks mentioned. Michael Douglass owns shares of Athenahealth. The Motley Fool recommends Athenahealth. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.