I've some concerns and queries, i observed that many altcoins even some major coins create fake volume, if a project is new and initially listed on a small exchange and create fake volume it's obvious understood that they're trying to get listed on coinmarketcap, but A coin which is existed in everywhere, even big exchanges but still they create fake volume on small exchanges, what this means? Why they do that? Is everything just done by exchanges or project itself, and also that makes a clear difference in prices as compared to official price of market that makes frustrated.
The technique of many Exchanges may be to increase the volume through bots, but it must be remembered that there is no consolidated volume that takes into account all Exchanges, that is why in each Exchange it has its own volume, not even CMC takes in It counts the volume of some Exchanges as localbitcoins, and Korean exchanges, and the study of the volumes is very important when making decisions for trading.
A good way to get an idea of the volume is to review the one shown by Bitfinex, Coinbase, which are Exchanges that handle a large number of traders and investors.