Didi Kuaidi, Uber's chief rival in China, reportedly invested in Lyft — Uber's biggest US rival — earlier this year, The Wall Street Journal reports. Didi Kuaidi was created in February when competing apps Didi Dache and Kuaidi Dache merged to cut the costs of competing with each other — and more importantly, with Uber. The ride-sharing and ride-hailing arms race in China is only heating up with Uber's biggest rival in the country making an investment in Uber's biggest US rival. Previously, Didi Kuaidi invested in GrabTaxi, a Singapore-based ride-hailing service, which closed a $350 million round of funding in...