Shift4 Payments (NYSE: FOUR) isn't quite as well known as some of its payment processing peers, but it has done a fantastic job of executing on its growth strategy. In fact, Shift4 produced all-time highs for payment volume, gross profit, and free cash flow in the third quarter, while its stock price lost 40% from its highs. A relatively small player compared to companies like Block (NYSE: SQ) and PayPal, Shift4 is building market share, with end-to-end payment volume more than quadrupling since 2019.