It was a rocky week on Wall Street, with Nasdaq stocks inching lower and the Dow inching higher, but there were plenty of stocks really making some serious moves. Let's take a closer look at five of this past week's biggest scorchers.


May 23

Weekly Gain







MannKind (NASDAQ:56400P706)



Maxwell Technologies (NASDAQ:MXWL)



Tableau Software (NYSE:DATA)



Source: Barron's.

Let's start with FireEye. The recent IPO moved higher despite lockup expirations, fueled by a pair of kind analyst notes. The week began with Nomura reiterating its bullish rating on the cyber-security specialist. Barclays Capital then upgraded FireEye, tagging it with a $40 price target.  

Gogo kept ascending after posting better-than-expected results a week earlier. UBS kicked off the new week by upgrading the stock. A day later, Gogo announced that it was teaming up with Apigee to create a new platform that will deliver innovative apps for passengers and crew members. Later in the week Gogo increased its order for in-flight radio modems, a strong sign that business is taking off. 

MannKind continues to gain ground a week after Piper Jaffray analyst Dr. Joshua Schimmer upgraded shares of the company behind Afrezza, an inhaled insulin solution. The chances are improving for Afrezza to clear regulatory approval this summer with a distribution partnership potentially in place before that. 

Maxwell Technologies moved higher after Piper Jaffray bumped its price target on the shares from $23 to $25. Piper Jaffray sees orders picking up at the Chinese bus company that happens be Maxwell's biggest customers.

Finally we have Tableau Software gaining ground on buyout chatter. This is the kind of talk mainstream analysts typically ignore, but Jim Cramer helped amplify the rumor by discussing it on CNBC's Mad Money. He relayed the talk, arguing that it would make a great fit for a tech giant now that its stock price has fallen sharply.

"The takeover chatter didn't make sense when Tableau was at $102, but at $54 where it started today," he wondered out loud on his show. "You can see how someone might take the M&A rumors seriously."