Micky Malka is the founder of Ribbit Capital and the co-founder of Node, the first gallery built for digital artists. He calls himself an entrepreneur at heart and an investor by design — a line vague enough to defy labeling, which is the point. The only label he wants is the one on his tombstone: He was a rebel.

At 25, Malka put every dollar from his first exit into a branchless bank in Brazil, moved there with his wife, and twice came close to killing the company and losing everything. At its peak, Lemon Bank ran 7,000 locations serving 50 million customers, most of them unbanked. He sold it in 2008. Twelve years later, the same insight persuaded Walmart to do a first — a jointly owned company. It became OnePay, the biggest financial brand you have never heard of.