Last Week's Biggest Stock Movers on Wall Street

Plenty of stocks go up and down in any given week. The gainers inspire us to keep investing. The decliners keep greed in check while reminding us about the risks of the equity markets.

Let's go over some of last week's best and worst performers.

Trevena (TRVN) -- Up 78 percent last week

One of last week's biggest winners was Trevena, moving higher after positive clinical trials results for its promising pain killer for folks undergoing tummy tuck procedures. Trevena's TRV130 treatment also proved superior to morphine in curbing some abdominoplasty side effects including nausea, vomiting, and hypoventilation.

%VIRTUAL-WSSCourseInline-1023%Vera Bradley (VRA) -- Up 33 percent last week

The company behind the colorful luggage, handbag and accessory merchandise saw its stock pop by nearly a third after posting encouraging quarterly results. Checking in with nearly 2 percent year-over-year growth in sales may not seem like much, but analysts were holding out for a decline. The bottom line is also holding up, and now Vera Bradley is boosting its profit forecast for the entire year.

Planet Fitness (PLNT) -- Up 11 percent last week

Shares of Planet Fitness -- the gym operator that prides itself on low-cost memberships -- got off to a slow start after going public four weeks ago, but the stock's been getting pumped up lately. Planet Fitness stock has closed higher in nine consecutive trading days, and a strong quarterly report on Wednesday afternoon only helped.

Revenue climbed to $79 million for the quarter, 26 percent ahead of the prior year's showing. Adjusted earnings grew even faster, up 29 percent to hit a better-than-expected profit of $0.13 a share. This is naturally Planet Fitness' first quarter as a public company, and it's always a good sign to kick things off with a strong report.

Vince Holding (VNCE) -- Down 42 percent last week

Last week's biggest sinker was Vince Holding, taking a big hit after posting terrible quarterly results. Sales declined sharply, as an uptick in sales at the retail level was no match for a sharp slump at the wholesale level.

The clothing company is in a state of disarray. It has lost its CEO, CFO and chief creative officer since June. The boardroom can be as fickle as fashion sometimes.

Netflix (NFLX) -- Down 16 percent last week

Shares of the leading premium video service fell every single trading day last week. Investors were scared earlier in the week after Variety reported that Apple (AAPL) was chatting up Hollywood executives in a move to secure original content for its yet-to-be-announced streaming television service.

AeroVironment (AVAV) -- Down 15 percent last week

Unmanned drones are cool, but AeroVironment wasn't last week after posting disappointing quarterly results. Sales fell short of Wall Street projections and AeroVironment's quarterly deficit was twice as bad as analysts were targeting. AeroVironment's vehicles may help keep troops out of harm's way by going on security missions, but it couldn't do the same for its shareholders.

Motley Fool contributor Rick Munarriz owns shares of Netflix. The Motley Fool owns and recommends AeroVironment, Apple, and Netflix. Try any of our Foolish newsletter services free for 30 days. Check out our free report on one great stock to buy for 2015 and beyond.