纽交所：
https://www.sec.gov/edgar/searchedgar/companysearch
纳斯达克：
https://secfilings.nasdaq.com/
参考：https://www.zhihu.com/question/25985393
参考：https://www.zhihu.com/question/21745113
参考：https://www.zhihu.com/question/21745113
参考：https://stockanalysis.com/stocks/aixi/
参考：https://secfilings.nasdaq.com/filingFrameset.asp?FilingID=11820081&RcvdDate=2/2/2017&CoName=SNAP%20INC&FormType=S-1&View=html
