In market terminology, a ‘bubble’ is defined as being when the price of an asset far exceeds its intrinsic value. The dotcom bubble that occurred between 1995 and 2000 is a prime example, where firms in the information technology industry saw their stocks rise merely because of the market sentiment around that particular industry, irrespective of their profits or chances of succeeding. The bubble then burst in March 2000 and companies went bankrupt, making their stock worthless.The value in most cryptocurrencies is derived from their potential; how they could be used to advance society in the future. While prices for bitcoin and other cryptocurrencies crashed in 2018, they surpassed the previous highs during the rally in 2020-2021, making larger gains for investors that held onto them over that period.It could be that bitcoin is not overvalued, and that the bubble, if there is one, is represented by the various new cryptocurrencies that are being driven exclusively by market sentiment. Arguably, this is comparable to the dotcom era – when stocks like Amazon (AMZN) were not overvalued, but others like Pets.com, which went from IPO to liquidation in 268 days – clearly were. However, there has been so much hype surrounding bitcoin so far during 2021, it’s currently anybody’s guess whether it will end the year up or down from its current position.Whether you believe the market is overheating or not, there is an option to trade crypto using CFDs to take both long and short positions.The views expressed in this article are those of the author and do not represent investment advice. Always remember your decision to trade depends on your attitude to risk, your expertise in this market, the spread of your investment portfolio and how comfortable you feel about losing money.