The PEG ratio divides the P/E ratio by expected earnings growth — answering "is this P/E justified by the growth?". A PEG around 1 means price roughly matches growth; below 1 suggests growth is underpriced. This heatmap colors US stocks by PEG, sized by market cap and grouped by sector.
Greener tiles have lower PEG (growth cheaper), redder tiles higher PEG. Companies without reliable growth estimates appear gray.
Peter Lynch's rule of thumb: PEG near 1 is fairly valued, below 1 is attractive, above 2 is expensive. The rule assumes stable growth — very high growth rates compress PEG artificially.
Trailing P/E divided by the expected earnings growth rate. Because both inputs are estimates of a moving target, treat PEG as a screening filter, not a verdict.
Low growth or declining earnings — a P/E of 10 with 3% growth gives a PEG above 3. PEG penalizes slow growers even when they look optically cheap on P/E.
Heatmap data updates through the trading session. Fundamentals come from Finnhub and SEC filings; scores are simplified heuristics for screening — not investment advice.