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.

Company

May 2

Weekly Gain

Westport Innovations (WPRT -1.73%)

$16.07

24%

Vonage (VG)

$4.22

15%

Rite Aid (RAD 12.50%)

$7.87

14%

Novavax (NVAX -1.94%)

$4.33

11%

Yandex (YNDX)

$26.53

11%

Source: Barron's.

Let's start with Westport Innovations. The provider of liquefied natural gas fueling solutions posted blowout quarterly results, propelled by a 39% surge in revenue and a narrowing quarterly deficit. Westport sees revenue climbing just 7% to 13% for all of 2014, but it feels as if its three operating business units will combine to achieve positive adjusted EBITDA by the end of this year. 

Vonage made a winning connection with investors after posting better-than-expected results, fueled by a 40% spike in its business solutions operations. The Web-based telephone service provider closed out the quarter with 13,000 more subscribers than it had when the period began. Adjusted earnings fell to $0.06 a share, but that was twice as much as analysts had been forecasting.  

Rite Aid moved higher after announcing impressive store-level performance metrics for April. The drugstore operator saw comps rise 5% for the four weeks ended April 26. Most of the growth at the front end of the chain's business was attributable to the shift in the Easter holiday, but there was still a healthy 5.2% spike in comps on the pharmacy end. Rite Aid's results became even more noteworthy after a rival posted uninspiring results.

Novavax shot up after the vaccine developer announced encouraging results for its RSV-F protein nanoparticle vaccine candidate in a mid-stage clinical trial in women of childbearing age. RSV -- or respiratory syncytial virus -- is a virus that causes respiratory infections.

Yandex bounced back after a rough week in which even Vladimir Putin called it out in his efforts to tighten online restrictions in Russia. Putin had picked on Russia's leading search engine, upset over its international investors and overseas influence. The situation remains fluid, but after the stock hit a 52-week low, investors feel there's an opportunity in the challenge.