# Market Monitor

> Daily U.S. stock-market breadth data, published as a static dashboard and an aggregate machine-readable JSON snapshot. The latest market session is first; the page is a market-awareness tool, not trading advice.

Market Monitor is generated after each available U.S. market session from locally archived daily OHLCV data. It is not scraped from a third-party website. The dashboard contains historical sessions and defaults to the newest available year.

## Primary resources

- [Interactive dashboard](./): Visual heat-map table with year tabs and metric explanations.
- [Machine-readable aggregate dataset](./market-monitor.json): JSON with an explicit schema, column definitions, session coverage, and rows ordered newest first.
- [Methodology and field guide](./methodology.md): Human- and agent-readable definitions, interpretation notes, and limitations.

## Data interpretation

- `up_4pct` and `down_4pct` count liquid U.S. securities moving at least 4% up or down on the session under the monitor's volume tests.
- `ratio_5d` and `ratio_10d` are rolling five- and ten-session totals of the 4% up count divided by the corresponding 4% down count. A missing value means the denominator is zero or the source value is unavailable.
- The quarter and month fields measure broad upside/downside momentum; `bull_34_13` and `bear_34_13` measure medium-term breadth; `x10atr` flags unusual daily-range expansion.
- `t2108` is this implementation's local equivalent of the percentage of eligible stocks above a 40-day average. It is a participation gauge, not an index quote.
- `universe` is the number of listed-universe securities with a valid bar for the session. `sp500` is the SPY ETF closing price used as market context.

## Scope and limitations

The JSON snapshot contains aggregate breadth metrics, not a per-ticker feed. Historical coverage, formulas, and caveats are stated in the linked methodology page and in the JSON `notes` field. Values are historical market data and should not be treated as personalized investment advice.