Add StreamXLS to Commercial & Proprietary Services (#531)

Co-authored-by: StreamXLS <307297713+streamxls-dev@users.noreply.github.com>
Co-authored-by: Wilson Freitas <wilson.freitas@gmail.com>

README.md

@@ -727,6 +727,7 @@ A curated list of insanely awesome libraries, packages and resources for Quants
 - [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.
+- [StreamXLS](https://streamxls.com) - Commercial Excel RTD server for the Interactive Brokers TWS API, streaming market data, account values, positions, and orders into Excel formulas on Windows.
 - [AtlasYield](https://atlasyield.club) - Independent rating and allocation layer for on-chain yield: scores every DeFi vault 0-100 across 16 factors, with a public read-only scores API. [GitHub](https://github.com/gveshk/atlasyield-score-history)
 - [Katana](https://katanascreener.com) - Free Japan stock screener built on EDINET filings. 160+ fundamentals, custom formula metrics, Graham/Piotroski/Kiyohara presets. No sign-up.
 - [Disclosed Capitol](https://www.disclosedcapitol.com/data-files/api) - US congressional and executive-branch stock trade disclosures API. STOCK Act filings plus OGE executive data (~6,743 transactions across 106 officials), with trade-level returns and alpha. Free tier: 500 credits, no card.