How to Add Stablecoin Settlement Without Rebuilding Your Stack

$8–25 per transfer. 2–5 business days to settle. 3–6 vendor integrations to maintain. Those are the real costs of a multi-vendor payment stack — and the exact numbers Polygon Open Money Stack is built to replace. This guide maps the four-layer model that collapses all three, with decision frameworks for fintech builders, enterprise treasury teams, and payment platforms evaluating stablecoin infrastructure in 2026.