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


May 31

Weekly Gain

Sonus Networks (NASDAQ:RBBN)






Infinera (NASDAQ:INFN)



AcelRX Pharmaceuticals (NASDAQ:ACRX)






Source: Barron's.

Let's start with Sonus Networks. The communications solutions provider moved sharply higher after Jefferies upgraded the stock form "hold" to "buy." Sonus also announced a partnership with Juniper Networks to develop software-defined network capabilities.

Clearwire got a boost after the bidding war for the company intensified. Charlie Ergen beefed up DISH Network's offer to $4.40 per share. The stock closed even higher than that on the week, as investors are anticipating higher bids as Dish and Sprint Nextel jockey for ownership of Clearwire.

Infinera closed higher every single trading day this past week. On Thursday, the digital optical networking specialist announced that it was able to raise some additional financing by issuing $140 million in convertible notes.

AcelRx moved higher after a director filed a purchase of 75,000 shares of the biotech. The buying activity comes a week after encouraging late-stage clinical trial data on the relief provided by AcelRx's pain management system.

Finally we have MAKO Surgical. Wells Fargo analyst Larry Biegelsen upgraded the stock from "market perform" to "outperform" on an upbeat outlook for the surgical robotics company's growth potential in hip replacement procedures. Biegelsen's replacing his earlier price target of $11 to $12 with a rosier goal in the mid-teens.

Longtime Fool contributor Rick Munarriz has no position in any stocks mentioned. The Motley Fool recommends Infinera, MAKO Surgical, and Wells Fargo and owns shares of Infinera and Wells Fargo. Try any of our Foolish newsletter services free for 30 days. We Fools don't 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.