On January 15, every one of the top 20 digital currencies by market value fell, apart from a pair of stablecoins (USD Coin and Tether.) This comes a day after cryptocurrencies experienced a brief rise. Bitcoin, which is the world's leading digital currency by market capitalization, fell a little more than 2%, ending the day at $3,615. It began the day trading at over $3,700, which is considered by some an important psychological level. It is further down from its high price for the week, which was reached on January 9 when the currency surpassed $4,100. Ripple, which is the second biggest digital currency by market value, fell nearly 3% during the course of the day. It is trading right now at about $0.32. The price of the currency, though, was mostly stable, avoiding large fluctuations. But it is still down considerably from its weekly high of $0.38, which it reached on January 9. While Bitcoin and Ripple suffered modest losses during the day, Ethereum — which is the 3rd largest digital currency by market capitalization — fared far worse. It fell about 7.5% and is currently trading at about $119. The cause of its fall may be related to a reported delay in a system upgrade. The upgrade, which is code-named Constantinople, has been highly anticipated in the Ethereum community. It was delayed a week because a critical vulnerability was found in it. As for the rest of the top 20 digital currencies, they all fell in a range from 2% to a little more than 7%. The two stablecoins — Tether and USD Coin — saw modest gains and are currently up 0.06% and 0.045%, respectively. The total market capitalization for all digital currencies is currently at about $120.5 billion, which is sharply lower than its weekly high of $138.6 billion. But not all cryptocurrency news is bad. A recent report from researchers at Diar found that digital currency exchanges around the world were involved in a record number of transactions during the course of 2018. In comparison with 2017, the number of trades and their volumes considerably increased at the top exchanges.