One of the largest fintechs in Europe has boosted its valuation following a secondary funding round from investors including BlackRock. "We will be further expanding in the US sooner rather than later," CFO Matt Briers told Business Insider. Now valued at $3.5 billion, the London-based fintech maintains its intention to one day go public. While an IPO is on the cards, "private markets are both strong and liquid for companies like us," he said. TransferWise today announced it had secured secondary funding worth $292 million, making it the fifth most valuable unicorn on the continent.