Brazilian fintech company StoneCo raised $1.2 billion in its debut on the U.S. public markets this week. Stone is similar to U.S. payments firm Square, facilitating e-commerce both online and in stores through partnerships with card companies and merchants. Jack Ma's Ant Financial and Warren Buffett's Berkshire Hathaway both took large stakes in the company as part of its public offering. Prior to the IPO, Madrone Capital Partners, an investment firm backed by heirs to the Walmart fortune, held a nearly 10 percent stake in Stone. The stock trades on the Nasdaq under the ticker symbol "STNE."
