LONDON — Bitcoin hit a new record high on Monday after smashing through the US$8,000 level for the first time over the weekend, marking an almost 50-per-cent climb in just eight days.

The new high came after leading U.S. payments company Square Inc (SQ.N) said late last week that it had started allowing select customers to buy and sell bitcoins on its Cash app.

Bitcoin traded as high as US$8,197.81 on the Luxembourg-based Bitstamp exchange, up over two per cent on the day and around 48 per cent up since dipping to US$5,555 on Nov. 12.

An eye-watering eightfold increase in the value of the volatile cryptocurrency since the start of the year has led to multiple warnings that the market is in a bubble, and institutional investors are broadly staying away.

Retail investors, however, as well as some hedge funds and family offices, are piling into the market. The "market cap" of all cryptocurrencies hit an all-time high of over US$242 billion on Monday, according to trade website Coinmarketcap.