Add Stingray to commercial services (#490)

Co-authored-by: Wilson Freitas <wilson.freitas@gmail.com>

README.md

@@ -708,6 +708,7 @@ A curated list of insanely awesome libraries, packages and resources for Quants
 - [Finterm](https://finterm.xyz) - `TypeScript` - Browser-based, keyboard-first financial terminal. No public GitHub repo (closed source).
 - [Coinugget](https://coinugget.com) - Real-time RSI signals, price action, and volume spikes dashboard across multiple exchanges. Free, no sign-up required.
 - [The Stall](https://the-stall.intuitek.ai) - `JavaScript` - 277 pay-per-call tools via MCP: US stocks, crypto, DeFi analytics, Polymarket prediction markets, macro data, and sanctions screening. USDC on Base. No API key required. [GitHub](https://github.com/thebrierfox/the-stall)
+- [Stingray](https://stingray.fi/) - Trading strategy builder that turns plain-English market ideas into inspectable rules, backtests them against historical data, and monitors matching live conditions.
 - [NeuPortal](https://neuportal.ai) - AI forecasting-accountability lab: every forecast is locked pre-event, Bitcoin-timestamped (OpenTimestamps), and Brier-scored against prediction markets in public.
 - [AlphaAssay](https://alphaassay.com) - `REST` - Independent statistical assay office for trading signals and backtests: deflated Sharpe with cumulative trial accounting, probability of backtest overfitting (PBO/CPCV), leakage forensics, placebo tests against matched synthetic null worlds, and pre-registration with Merkle-anchored timestamps — deterministic, Ed25519-signed verdicts anyone can replay. Free demo; hosted API and MCP server. Methodology audit, not investment advice. [GitHub](https://github.com/alphaassay/mcp)
 - [Market Posture Daily](https://marketpd.com) - Daily trend, regime, momentum and relative-strength data for ~90 crypto assets and US stocks/ETFs, with a cointegration pair screener. Free terminal + JSON API.