Revolut, a London-based digital banking startup, raised $250 million in new funding at a $1.7 billion post-money valuation.

Why it's a big deal: Revolut's growth is astounding, even within the context of London's burgeoning digital banking sector (e.g. TransferWise, Monzo, etc.).

It claims to have doubled its customer base to two million in the past five months and reports 250,000 daily active users — all just three years after initial product launch.

• Investors: DST Global led, and was joined by Index Ventures and Ribbit Capital.
• Bottom line: "Revolut offers most of the features you’d expect of a current account, including physical and virtual debit cards, direct debits and money transfer. Its 'attack vector' (to borrow Monzo’s Tom Blomfield’s phrase) was originally low exchange fees when spending in a foreign currency, which undoubtedly fueled much of the startup’s early growth." — Steve O'Hear, TechCrunch