China's second-largest e-commerce company JD-dot-com has filed a complaint to the Chinese antitrust regulator and formally requested an investigation into rival Alibaba Group. This comes just before Alibaba's annual Singles Day online shopping frenzy. JD accused Alibaba of forbidding merchants to participate on other e-commerce platforms if they choose to join the Singles Day sales promotion on Alibaba's Tmall. Alibaba denies JD's allegation, and says it will leave the choice to consumers.