MSCI provides data, analytics, and indexes that institutional investors use to construct and manage investment portfolios. MSCI's roughly 6,800 clients span asset managers, hedge funds, banks, pension funds, sovereign wealth funds, and insurance companies across more than 100 countries. BlackRock is MSCI's largest client at roughly 11% of consolidated revenues. MSCI operates four segments: Index (~57% of revenue), Analytics (~23%), Sustainability and Climate (~11%), and Private Assets (~9%). The Index business is MSCI's flagship, where clients use MSCI indexes — including MSCI World, MSCI ACWI, and MSCI Emerging Markets — for benchmarking, ETF construction, and portfolio management. The Analytics segment provides risk management and performance attribution tools, including the widely-used Barra equity factor models. The Sustainability and Climate segment offers ESG ratings and climate risk data on a subscription basis. The Private Assets segment covers commercial real estate data and private capital analytics, built on the Real Capital Analytics and Burgiss acquisitions. MSCI generates revenue through two mechanisms: recurring subscriptions (~57% of run rate), where clients pay fixed fees for deeply embedded data and tools with retention rates above 94%, and asset-based fees (~26% of run rate), where clients pay a fee in basis points on AUM linked to MSCI indexes — approximately $7 trillion in total, including ~$2.2 trillion in ETFs. MSCI's economics benefit from strong operating leverage: MSCI creates intellectual property once and licenses it to many clients at high incremental margins.