Flex vs Block
Side-by-side comparison of AI visibility scores, market position, and capabilities
US YC S23 HSA/FSA payment infrastructure for DTC health brands; $18M total ($15M First Round/Core VC Series A Sep 2025 + $3.2M seed) enabling Stripe-like online pre-tax health spending competing with Truemed for $150B HSA/FSA market.
About
Flex is a United States-based HSA/FSA payment infrastructure platform — backed by Y Combinator (S23) with $18 million in total funding including a $3.2 million seed in September 2024 from Y Combinator, SV Angel, Precursor Ventures, and Liquid 2 Ventures, plus a $15 million Series A in September 2025 led by First Round Capital and Core VC with Cameron Ventures, Rethink Impact, and Y Combinator — providing direct-to-consumer health and wellness brands with Stripe-like payment processing infrastructure that enables online acceptance of HSA (Health Savings Account) and FSA (Flexible Spending Account) funds from the $150+ billion annual pre-tax healthcare spending market. Founded in 2023 by Sam O'Keefe and Miguel Toledo, Flex targets the DTC health and wellness brands that cannot currently accept HSA/FSA payments online because of technical and compliance barriers.
San Francisco fintech (NYSE: SQ) added to S&P 500 July 2025; Cash App $5.0B gross profit, Square $3.7B, Afterpay BNPL integration, Jack Dorsey CEO competing with PayPal/Venmo and Stripe for merchant and consumer fintech.
About
Block, Inc. is a San Francisco, California-based financial technology company — publicly traded on the New York Stock Exchange (NYSE: SQ) as an S&P 500 Information Technology component (added to the S&P 500 on July 23, 2025, replacing Hess Corporation) — operating two primary financial platforms: Square (merchant payment processing, point-of-sale hardware, and business banking for small-to-mid-size merchants) and Cash App (peer-to-peer payments, digital banking, stock investing, and Bitcoin transactions for individuals) alongside Afterpay (buy now pay later), Tidal (music streaming), and TBD (decentralized finance), through approximately 12,000 employees. CEO Jack Dorsey (co-founder with Jim McKelvey in 2009 as Square, rebranded to Block in December 2021) leads the company's strategy of building an interconnected ecosystem of financial services that connect individual consumers (Cash App) with merchants (Square) and the broader financial ecosystem. In fiscal year 2024, Block reported gross profit of approximately $8.9 billion, with Cash App generating approximately $5.0 billion in gross profit (+14% year-over-year) driven by Cash App Card, direct deposit adoption, and Cash App Pay, while Square generated approximately $3.7 billion in gross profit (+9%) driven by software and banking products alongside payment processing. Block acquired Afterpay for $29 billion in January 2022 — integrating the Australian buy-now-pay-later platform into both Square (merchant installment offer at checkout) and Cash App (consumer Afterpay integration).
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