Redstone Markets

Redstone is free return and risk analytics for about 2,900 US stocks and 1,200 ETFs. It shows total returns with dividends reinvested, plus Sharpe, Sortino, max drawdown, beta and correlation, and supports comparisons, portfolio backtests and screens. No account is needed. A public read-only MCP server at https://redstonemarkets.com/api/mcp (Streamable HTTP, no API key) lets ChatGPT, Claude and other assistants query the data. Docs and the agent skill are in the MIT repo https://github.com/mihaitv/redstone-mcp.