I think that will be a prediction on how many people involved in the cryptocurrency, but we don't know the right number. Perhaps, the number will be more than that article because, with the internet connection everywhere, I am sure that people can read information about cryptocurrency from many website including in social media.
But that could be a good article for us, and we can know how many people who are joined with the cryptocurrency so far, and I am sure that the number will increase more in the future.