African cryptocurrency exchange Yellow Card has concluded a $15 million Series A financing round led by some of blockchain’s biggest venture funds, underscoring the growth potential of digital assets on the continent.  The fundraiser, which was described as the largest ever by any African cryptocurrency exchange, will enable Yellow Card to scale its operations across Africa and onboard new talent, the company announced Monday. The Series A came roughly one year after Yellow Card successfully raised $1.5 million from various investors. The investment round was led by Valar Ventures, Third Price and Castle Island Ventures with additional participation from Square, Inc., Blockchain.com Ventures, Coinbase Ventures, Polychain Capital, BlockFi, MoonPay and others.