Generally the biggest bitcoin exchanges to buy cryptocurrency will be toward the top of the above list. For example Bitfinex, GDAX, Bitstamp, Coinbase (also the best usd bitcoin exchange) all represent large volume proportions. Daily volume varies, and therefore the world’s largest cryptocurrency exchange vary each day. Go to bitcoinity for a good list of all the best bitcoin exchange site to buy cryptocurrency and their proportional volumes. Some find this handy for arbitrage between markets.
Bitcoin and other cryptocurrencies have been identified as economic bubbles by at least eight Nobel Memorial Prize in Economic Sciences laureates, including Robert Shiller,[192] Joseph Stiglitz,[193] and Richard Thaler.[194][13] Noted Keyensian economist Paul Krugman wrote in his New York Times column criticizing bitcoin, calling it a bubble and a fraud;[195] and professor Nouriel Roubini of New York University called bitcoin the "mother of all bubbles."[196] Central bankers, including former Federal Reserve Chairman Alan Greenspan,[197] investors such as Warren Buffett,[198][199] and George Soros[200] have stated similar views, as have business executives such as Jamie Dimon and Jack Ma.[201]
All of those factors make mining cryptocurrencies an extremely competitive arms race that rewards early adopters. However, depending on where you live, profits made from mining can be subject to taxation and Money Transmitting regulations. In the US, the FinCEN has issued a guidance, according to which mining of cryptocurrencies and exchanging them for flat currencies may be considered money transmitting. This means that miners might need to comply with special laws and regulations dealing with this type of activities.

The growing popularity of bitcoin as an alternative investment has drawn the attention of forex brokers who are looking to expand their offerings. Some define bitcoin as a traditional currency, especially since the trading of bitcoins is not based on macroeconomics of a nation, but instead the underlying platform and broader reaction to shifts in global economics.

In January 2009, the bitcoin network was created when Nakamoto mined the first block of the chain, known as the genesis block.[19][20] Embedded in the coinbase of this block was the following text: "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks."[10] This note has been interpreted as both a timestamp and a comment on the instability caused by fractional-reserve banking.[21]:18