athenahealth, Inc (NASDAQ:ATHN) shares climbed nearly 18% after activist hedge fund manager Paul Singer of Elliott Associates disclosed a 9.2 percent stake in the clinical software maker.

Singer believes that “the securities of the Issuer are significantly undervalued and represent an attractive investment opportunity.” The reason?  “The Issuer operates in a highly strategic area at the intersection of technology and healthcare with a disruptive value proposition, a leading competitive position and a compelling product set, the value of which is not reflected in the Issuer’s current market value.”

As there are numerous operational and strategic opportunities to maximize shareholder value, Persons will be seeking to engage in a dialogue with athenahealth’s Board of Directors regarding these matters.

In reaction, Evercore ISI Ross Muken raised his price target on ATHN to $147.00 (from $118) while reiterating an Outperform rating on the stock.

“While the filing surprised many, it is not altogether shocking that a relatively underperforming, though strategically well-placed asset would attract activist attention. We believe there are two obvious paths for value creation: 1) work with management to improve the operating structure and enhance FCF creation by streamlining investment and emphasizing total returns over growth at all costs or 2) Explore a strategic event (LBO, strategic sale to tech or HC service entity),” Muken noted.

According to TipRanks.com, which measures analysts’ and bloggers’ success rate based on how their calls perform, analyst Ross Muken has a yearly average return of 21.1% and a 82.7% success rate. Muken has a -15.5% average return when recommending ATHN, and is ranked #149 out of 4561 analysts.

Out of the 19 analysts polled by TipRanks (in the past 12 months), 12 rate Athenahealth stock a Buy, 5 rate the stock a Hold and 2 recommend to Sell. With a downside potential of 3%, the stock’s consensus target price stands at $121.50.

athenahealth, Inc. provides cloud-based business services and mobile applications for medical groups and health systems. It also provides ongoing billing, clinical-related, and other related services to customers. The company offers practice management and electronic health record services. Its service offerings are based on proprietary web-native practice management and electronic health record software, which offer payer knowledge-base and integrated back-office service operations and care coordination services. The company’s cloud-based software offers four integrated offerings through athenaNet; athenaCollector for revenue cycle management; athenaClinicals for clinical cycle management; athenaCommunicator for patient cycle management; and athenaCoordinator for referral cycle management.