I didn't realize $SQ was run by $TWTR CEO Jack Dorsey: "San Francisco-based Square, run by Twitter CEO Jack Dorsey, is well-known in the payments sector for its credit card processor, payment hardware and popular Cash App. Gross payment volume, or GPV, on the Cash App grew roughly 150 percent year over year. Last quarter, Square’s peer-to-peer Cash App reported more than 15 million monthly active customers in December 2018, doubling from a year earlier. "