https://blog.wongcw.com/2019/04/13/uber%e7%a8%b1%e5%b0%87%e6%96%bc4%e6%9c%8826%e6%97%a5%e5%95%9f%e5%8b%95ipo%e8%b7%af%e6%bc%94%ef%bc%9a%e9%96%8b%e5%a7%8b%e6%8b%9b%e6%94%ac%e6%8a%95%e8%b3%87%e8%80%85/