NEW DELHI: One of the most extravagant predictions sees bitcoin at $1 million within three years. But that's a story for another time.Bitcoin, undoubtedly the most talked about asset class today, has spurted over 1,500 per cent on a year-date-basis so far and over 115 per cent in the past one month.But a little known cryptocurrency has put to shame the meteoric rise in bitcoin.With a rally of astounding nearly 1,000 per cent in the past one month alone, IOTA is now the fourth biggest crytocurrency in terms of market capitalisation after bitcoin, ethereum and bitcoin cash.Prices of IOTA surged 980 per cent to $4.14 on December 7, 2017 from $0.38 on November 7. The e-currency has surged over 180 per cent in December so far.According to coingecko.com, IOTA is a distributed ledger for the Internet of Things. The first ledger with microtransactions without fees as well as secure data transfer.Announcement of partnership with major companies like Microsoft can be considered as one of the reasons for the recent surge in the prices of IOTA.“We are excited to partner with IOTA foundation and proud to be associated with its new data marketplace initiative. This next generation technology will accelerate the connected, intelligent world and go beyond blockchain that will foster innovation real world solutions, applications and pilots for our customers,” Microsoft’s Omkar Naik in a statement published on the IOTA Foundation website.In terms of market capitalisation, bitcoin has the highest market cap of Rs 18.46 lakh crore. It is followed by ethereum (Rs 2.80 lakh crore), bitcoin cash (Rs 1.66 lakh crore) and IOTA (Rs 0.71 lakh crore).In rupee terms, IOTA is hovering at around Rs 258.Other cryptocurrencies, including bitcoin, ethereum and bitcoin cash is trading at Rs 11 lakh, Rs 29,100 and Rs 98,000 lakh, respectively. Ripple was trading at Rs 16.41, according to the data available with coingecko.com.A cryptocurrency is a digital currency created and stored electronically. The supply of this currency is not determined by any central bank or authority and the network is completely decentralised.One cannot directly buy IOTA in India but can exchange bitcoin for IOTA on couple of websites including Binance.IOTA was founded in 2015 by David Sønstebø, Sergey Ivancheglo, Dominik Schiener and Serguei Popov.Back home, The Reserve Bank of India on Tuesday reiterated its concerns about Bitcoins, stoking fears that a rapidly swelling bubble could burst in a spectacular fashion.The Central Bank said it wanted to reinforce its previous message to “users, holders and traders of Virtual Currencies (VCs) including bitcoins regarding the potential economic, financial, operational, legal , customer protection and security related risks associated in dealing with such VCs.”The RBI had earlier said those trading in VCs were doing so at their own risk, given that the central bank has not given a licence or authorisation for any company to deal in such cryptocurrencies.