Bitcoin is too small probably because they see the time of 2013 is still very few who use Bitcoin, but also many who do not know Bitcoin. I'm sure by 2013 maybe only 5% know Bitcoin. How Bitcoin's growth from 2013 to 2017 is so significant, in 2017 alone we can see very rapid developments, and many even make Bitcoin's prediction of $ 10,000 / BTC. I myself am very confident Bitcoin will definitely break through $ 10,000 / BTC at the end of this year.