Last Week's Biggest Stock Movers

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.

Aquinox Pharmaceuticals (AQXP) -- Up 112 percent last week

The market's biggest winner last week was Aquinox Pharmaceuticals, more than doubling after revealing positive mid-stage clinical trial results. Aquinox is trying to get a treatment for eczema and bladder pain approved, and the encouraging results suggest that it will happen.

Wayfair (W) -- Up 36 percent last week

The Web-based furniture retailer soared after posting blowout quarterly results. Wayfair saw its sales soar 66 percent since the prior year, and its loss was only half as much as Wall Street was expecting. Wayfair's online platform continues to attract new furniture shoppers. Its active customer count now stands at 4 million, 54 percent ahead of where it was a year ago.

magicJack (CALL) -- Up 25 percent last week

Another big winner last week was magicJack. The company behind the namesake Internet-based phone service connected with investors after posting better-than-expected financials. Revenue did post a year-over-year drop in its latest quarter, but shrewd cost-cutting helped deliver a strong pop in profitability. The eventual adjusted profit of 30 cents a share was well ahead of the 19 cents a share that the pros were forecasting.

There are now 2.62 million subscribers to magicJack's platform. Its monthly churn clocked in at 2.8 percent, and while that may seem like a lot of turnover, it's actually magicJack's best churn rate in several years.

Christopher & Banks (CBK) -- Down 47 percent last week

The New York Stock Exchange's biggest sinker was Christopher & Banks. The specialty women's apparel retailer warned that sales for the quarter that will end later this month will clock in closer to $94 million. The chain's earlier guidance called for $100 million to $103 million in net sales.

%VIRTUAL-WSSCourseInline-538%Christopher & Banks started to experience weakness in late June across all of its product categories, and that hasn't improved through the summer. It now sees comparable-store sales plunging 12.4 percent since the prior summer. That would be acceptable if Christopher & Banks were scoring generous markups on those diminished sales, but margins are also going the wrong way. It's not a pretty situation, and Christopher & Banks is bringing in an outside consultant for an operational review.

Papa Murphy's (FRSH) -- Down 26 percent last week

The top dog in take-and-bake pizzas that are assembled at its stores but customers bake at home slumped after posting quarterly results. It wasn't a bad performance. Revenue climbed 33 percent since the prior year, juiced up by the expansion of company-owned stores and a 4.5 percent uptick in comparable-store sales. That was actually ahead of Wall Street's expectations.

Papa Murphy's adjusted profit of 9 cents a share was in line with analyst targets, but the chain spooked the market by raising its guidance for capital expenditures this year, something that could sting on the bottom line even if it results in more company-owned stores opening. Even with the big hit last week, the stock is still beating the market this year with a 28 percent gain so far in 2015.

King Digital Entertainment (KING) -- Down 12 percent last week

Finally, we have the mobile gaming giant behind "Candy Crush Saga" and "Farm Rescue Saga" getting crushed after offering up weak financials. Once again we're seeing gross bookings, revenue, and earnings continuing to slide. "Candy Crush Saga"'s financial performance peaked in the latter half of 2013, and pushing out several new games hasn't been able to offset the slide. The number of active paying players has fallen 27 percent across all of King's games, and that's not going to sit well with Mr. Market.

Motley Fool contributor Rick Munarriz has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. 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.