The Week's Top Stories is a guided tour through the biggest market stories of the week, from winning stocks to brutal dips to the facts and forecasts generating buzz on Wall Street.  
Lyft shares initially popped following the announcement that co-founder Logan Green is stepping down and David Risher, formerly of Amazon and Microsoft, will take over day-to-day operations. The stock then declined as the bear case against the company, which has struggled to generate profits or keep up with rival rideshare giant Uber, won the day. For more context, check out Cheddar News Senior Reporter Michelle Castillo's interview with Risher about his plans for the company. 
Alibaba is splitting into six different business groups, and investors appear excited about the opportunities the new companies will generate. Shares of the Chinese company shot up 8 percent on Tuesday and is on track to finish the week up around 17 percent. Here are the names of the six new groups: Cloud Intelligence Group, Taobao Tmall Business Group, Local Services Group, Global Digital Business Group, Cainiao Smart Logistics, and Digital Media and Entertainment Group. Alibaba said each company will raise capital on its own and pursue its own initial public offerings. 
Virgin Orbit announced on Thursday that it's planning to lay off 85 percent of its workforce or 675 workers. The company has struggled to secure funding after a failed mission three months ago. The botched January mission would have been the first satellite launch from Europe, and its failure was seen by many as a major setback for both the company and the space industry on the continent. Virgin Orbit later admitted that the launch failed because its rocket's fuel filter disconnected.  
Shares of Lululemon Athletica jumped 13 percent after the retailer reported an earnings beat for the crucial holiday quarter. The company also reported an optimistic outlook for the year, as demand for activewear remains steady. The beat gave a boost to other athleisure brands such as Nike, Adidas, and Puma.