The price of bitcoin surged 8 percent to $750 on Thursday, its highest since early 2014, as jittery investors sought shelter in the web-based currency, once considered too volatile to invest in, let alone at times of market stress.
Worries that Britain will vote next week to leave the European Union, as well as concerns over global growth, have pushed down stocks and oil prices, while low-risk assets such as gold and top-rated government debt have risen.
Along with those conventional safe havens, investors have also turned to bitcoin.
The "cryptocurrency", which can move money across the globe quickly and anonymously with no need for a central authority, has climbed almost 70 percent over the past four weeks on the Luxembourg-based Bitstamp exchange. Gold, by comparison, has rallied almost 5 percent during the same period.
Daniel Masters, a former commodities trader who runs Jersey-based bitcoin hedge fund Global Advisors, said he had started to see commodity trading advisors put bitcoin into their portfolios "over the past month or two".
"Bitcoin is a global, frictionless, instantaneous form of currency, and it has a fixed supply. In this day and age, that ... is becoming very appealing," Masters said.
Other currencies had been weakened by the huge money-printing programmes implemented in recent years by central banks. With the yuan hitting a five-year low on Wednesday , bitcoin traders said demand from China was also driving up the cryptocurrency.
"If you're a Chinese investor ... you're looking at two things: you want to buy something that has momentum, and you want to buy something that in the current environment in China, with a devaluing currency, a shaky stock market, a very shaky real estate market and a very weak credit market, is truly uncorrelated," Masters said.
Around 95 percent of bitcoin trade is via Chinese exchanges, according to industry website Coindesk, so any increase in demand from China tends to have a significant impact.
Bitcoin's lack of central authority makes it attractive to those wanting to get around capital controls, such as those in China.
"Although Bitcoin is nascent, it fits the bill as a form of digital gold and as a route to evade capital controls," said Charles Hayter, CEO of London-based digital currency analysis website CryptoCompare.
Another reason given by bitcoin experts for the currency's latest surge is that on July 10, the number of new bitcoins that are added to the system every day will be halved. That slower growth in supply should raise the currency's value. (Reporting by Jemima Kelly, editing by Larry King)