Year-to-date performance measures return since the first trading day of the year — the scoreboard every fund manager reports against. This heatmap colors US stocks by YTD return, sized by market cap and grouped by sector, so the year's real leadership (and its disasters) are visible in one frame.
Greener tiles are the year's winners, redder tiles its losers — the annual leaderboard rendered as a map.
It is the universal comparison frame — funds, media and indices all report YTD. Knowing who leads the year explains what the market is currently rewarding.
Sometimes — momentum is real but mean-reversion is too, especially into year-end when funds rebalance and tax-loss sell the losers.
As a filter, not a verdict — some are broken businesses, some are quality names on sale. The Piotroski or FCF-margin views separate the two.
Heatmap data updates through the trading session. Fundamentals come from Finnhub and SEC filings; scores are simplified heuristics for screening — not investment advice.