Bitcoin is not at a size where it would pose a risk to the global economy, Bank of England Deputy Governor Jon Cunliffe said on Wednesday, as the virtual currency soared to a record high above $10,000 on major exchange.
The cryptocurrency has climbed 10-fold so far this year, the largest gain of all asset classes and prompting sceptics to warn it is a classic speculative bubble.
"I would just say investors kind of need to do their homework," Cunliffe told BBC Radio.
He said he did not think British households as a whole were going on a "debt-fuelled binge" but added that fast rates of consumer credit growth needed to be watched.
Cunliffe was in the minority of officials to vote against a rise in interest rates that took place earlier this month.
Asked why in a separate BBC radio interview, Cunliffe said that although he agreed with his colleagues that Britain's potential rate of economic growth had slowed since the financial crisis, he wanted to see more sign of inflation pressure.
"My view was given the disappointments we've had about pay increases and domestic cost pressures over recent years, we should wait to see those before raising rates."