The fintech giant has hit the milestone 15 years after it was founded by brothers Patrick and John Collison.Stripe was "robustly" cash flow positive in 2023 and expects to be again in 2024, says the firm in its annual letter, adding: "This threshold is important, because it allows us to invest for the long term."Last month, the fintech struck a deal with investors that will enable employees to cash out their shares in an offering that values it at $65 billion, up from $50 billion in 2023 but still well down on the $95 billion it was tagged with in 2021.In its letter, Stripe stresses that it is no longer just about payments, but revenue and finance automation, which it expects to being in an annual revenue run rate of more than $500 million over the next year.