The cryptocurrency market has remained under pressure this week, as prices of digital currencies, including bitcoin (BTC) and ripple, tumbled nearly 20 per cent between January 5 and 12 amid talks that South Korea was mulling a trading ban on digital currenciesSome analysts feel such an action by Seoul may push other nations to consider similar moves.A Wall Street consultancy on Thursday predicted a major crash in the cryptocurrency market this year.“After significant testing, we calculated the price of BTC 1 to be $1,780,” businessinsider.com quoted from a Quinlan & Associates report.On Thursday, media reports said Indian billionaire Mukesh Ambani ’s telecom venture Reliance Jio may launch its own cryptocurrency, JioCoin , shortly.Ambani’s new bet, a Mint report claimed, is the mandate of a 50-member team working on blockchain technology, which is being helmed by Ambani's elder son Akash.Businessinsider said the 156-page report of Quinlan & Associates argued that bitcoin’s current price near $14,000 was far above what it is worth as both an investment asset, akin to gold , and a payment mechanism.“As an asset, we valued bitcoin using a cost of production approach and a store of value approach, resulting in values of $2,161 and $687, respectively. To value BTC as a currency, we estimated its utilisation for both legal , retail transactions payments, as well as payments in the black market. After significant testing, we calculated the price of BTC 1 to be $1,780,” said the report.If the digital currency were to fall to this level, it would plunge a massive 85 per cent in the coming 12 months.Bitcoin prices soared from under $1,000 to almost $14,000 during calendar 2017, and ethereum jumped from about $8 to $734.On Wednesday, investment guru Warren Buffett said he would never invest in cryptocurrencies. “I can say almost with certainty that cryptocurrencies will come to a bad end," Buffett told CNBC in an interview.Bitcoin remains the top dog in the cryptocurrency market, but has tanked to $13,580 as of January 12 from $16,917 on January 5, whereas ripple slipped to $2 from $2.50. Bitcoin Cash and Litecoin have slipped over 5 per cent each in the same period.On the other hand, ethereum has soared 25 per cent to $1,204 as of January 12 from $962.77 on January 5.Bitcoins or cryptocurrencies are not a legal tender in India and are not recognised as a medium of exchange, Corporate Affairs Minister Arun Jaitley said on January 5.