US Equity Market Breadth API

How broad the US stock market's move really is under the surface, computed live from Yahoo Finance across a large-cap universe (no key, nothing stored). The S&P 500 can be dragged up by a handful of megacaps while most stocks fall; breadth tells you how many stocks are actually participating. The breadth endpoint scans a ~50-name large-cap universe spanning every sector and returns the share trading above their 20-, 50- and 200-day moving averages (the classic participation gauges), the advancers versus decliners on the day, the advance/decline ratio, the average and median daily change and a regime label (broad strength, mixed or broad weakness). The components endpoint returns the per-stock table behind it — each name's price, daily change and whether it is above each moving average — so you can see exactly which stocks are carrying or dragging the market. The constituents endpoint lists the universe. The equity market-internals / breadth cut — distinct from the crypto-breadth API (which scans coins), the single-quote, index-constituent and movers APIs. It answers whether a rally is broad or narrow, not how one stock is doing.