Among Wall Street’s greats, Carl Icahn is in a league of his own.

#-ad_banner-#With the power to sway a stock’s price in 140 characters or less — see Apple’s (Nasdaq: AAPL) 9% increase last August after he announced a position via Twitter), the legendary activist investor is a forced to be reckoned with. The “Icahn effect” can lead to sentiment-driven price gains after he announces a position as investors scramble to follow his moves.

Thanks to big returns from Netflix (Nasdaq: NFLX) and Herbalife (NYSE: HLF) in the past few years, Icahn’s net worth has skyrocketed to north of $20 billion. He is looking to pad that number with his 12.5% stake in medical imaging company Hologic (Nasdaq: HOLX), disclosed last October.

Could Hologic be Icahn’s next big winner, or will it continue its current trend of going nowhere fast?

Hologic manufacturers and supplies diagnostic systems and tests, predominantly X-ray bone densitometers and ultrasound bone analyzers. These tests have large implications for women’s health care, specifically in the diagnosis and treatment of osteoporosis and cancer.

Despite its promising intentions, Hologic has failed to turn a profit in five of the past six years. Most recently, the company reported a loss of $0.02 per share for its fiscal first quarter. Revenue was down nearly 5% year over year at $612 million. On the plus side, Hologic reduced its long-term debt by over 10%, though its debt load is still quite large at over $4 billion (thanks to its purchase of molecular diagnostics company Gen-Probe in 2012).

Hologic expects revenue for the current quarter to be slightly above consensus estimates but slightly down from the same quarter last year. Another positive came in the form of slightly higher EPS guidance for the full year.

To kick-start Hologic’s turnaround, Icahn has added two of his own representatives to its board. The company has also placed Stephen MacMillan, the former CEO of medical technology firm Stryker (NYSE: SYK), at its helm.

MacMillan brought smart strategic planning and expansive growth to Stryker. The Street is hoping that he won’t destroy shareholder value for Hologic by overpaying for big acquisitions like the aforementioned Gen-Probe deal and its 2007 acquisition of Cytyc, both made on the previous CEO’s watch. On the contrary, divesting assets and paying down debt are on the menu with the push of Icahn’s board members, and MacMillan has made it a priority to improve operating performance and growth for this year.

Looking back over the past year, the stock has traded in a fairly tight range, unable to push much higher than $23. The announcement of Icahn’s stake has not had a material effect on HOLX thus far in 2014.

However, lackluster performance in stock price has not deterred Icahn from investing in the past. Lest we forget, Icahn began building a position in NFLX in late 2012 around the $58 mark. At that time, Netflix was sorely overshooting new subscriber expectations, adjusting future guidance down, and the stock was suffering double-digit down days following poor earnings.

Herbalife, in which Icahn disclosed a large stake early last year, spent 2012 falling from a high above $72 to below $30 by year’s end. HLF hit a record high near $82 last month.

Risks to Consider: Icahn’s picks do not always work out as planned. For instance, he recently and famously submitted to Michael Dell after Dell fought to take his company private. While it’s tempting to mimic Icahn’s actions outright, understanding his investments and intentions make for a stronger argument than blindly following his moves.

Action to Take –> Whether growth or a possible sale is in the future, current levels are ripe for those wishing to get in at similar prices as Icahn. Short-term traders and those hoping for a quick sell need not apply. The new CEO’s stated intent is to expand the business, not to sell it.

P.S. As the world’s foremost activist investor, Carl Icahn focuses on unlocking shareholder value. Our resident dividend expert, Nathan Slaughter, just released a special report that shows how companies that put shareholders first generate the highest returns with the least risk. To learn more about how this strategy has beaten the market hands-down over the past 30 years, click here.