Dogecoin, "an open source peer-to-peer cryptocurrency, favored by Shiba Inus worldwide" now accounts for more transaction volume than every other cryptocurrency combined, including Bitcoin, Litecoin and Quarkcoin.Bitcoin has been criticized for its use in illegal transactions, its high electricity consumption, price volatility, thefts from exchanges, and the possibility that bitcoin is an economic bubble. Bitcoin has also been used as an investment, although several regulatory agencies have issued investor alerts about bitcoin.