pythonyfinancemassivepolygonfrededgarafter-workmarket-data
Is yfinance still reliable in 2026? Polygon is Massive — and a free official backup stack
yfinance is fine for after-work learning with a disk cache—not a live feed. Layer keyed REST (Massive, ex-Polygon), FRED, and SEC EDGAR; use Stooq CSV failover; migrate api.polygon.io on a checklist. Not investment advice.