Mercury, the fintech ambitious companies use for banking, credit cards, and software to power all their financial workflows, announced a $300 million Series C investment round from existing and new investors. The round, led by new investor Sequoia Capital, includes primary and secondary funding and values Mercury at $3.5 billion post-money, more than double its previous Series B valuation of $1.6 billion in 2021. Other new investors include Spark Capital and Marathon as well as participation from existing investors Coatue, CRV, and Andreessen Horowitz.