5 of Last Week's Biggest Winners

What's better than momentum? Mo' momentum. Let's take a closer look at five of this past week's biggest scorchers.

Source: Barron's.

Let's start with Halozyme Therapeutics. The biotech's goal of getting a breast cancer drug administered by subcutaneous injection cleared an important hurdle this past week, when a European regulator gave it a positive recommendation. Going the subcutaneous injection route shaves a lot of time for doctors and patients when compared with the current intravenous treatment.

Westport Innovations fueled higher as low natural gas prices make it more cost effective for fleets to swap out gas or diesel engines for systems powered by liquefied natural gas. Westport also announced small acquisitions on Friday that will make it the largest player in the North American light duty natural gas vehicle market.

American Supercondutor rose after a U.S. prosecutor charged a Chinese wind turbine company with stealing trade secrets from American Superconductor. China's Sinovel was American Superconductor's largest customer, accounting for more than two-thirds of its business four years ago. American Superconductor is seeking $1.2 billion in damages in Chinese courts.

Molycorp moved higher after announcing on Thursday night that the SEC completed its investigation of the rare-earth minerals specialist's public disclosures. The SEC is recommending that no enforcement action be taken at this time. 

GT Advanced Technologies was upgraded -- from "hold" to "buy" -- at Canaccord Genuity. Analyst Jonathan Dorsheimer thinks orders for polysilicon equipment should pick up in about a year, and without expecting an actual eruption in solar demand, he's comfortable in boosting GT's price target from $4 to $5.