diff --git a/README.md b/README.md
index 50bcfce..5eb174f 100644
--- a/README.md
+++ b/README.md
@@ -411,6 +411,7 @@ A curated list of insanely awesome libraries, packages and resources for Quants
   - [PyQL](https://github.com/enthought/pyql) - Python port.
   - [QuantLib.jl](https://github.com/pazzo83/QuantLib.jl) - Julia port.
 - [TA-Lib](https://ta-lib.org) - perform technical analysis of financial market data.
+- [Portfolio Optimizer](https://portfoliooptimizer.io/) - Portfolio Optimizer is a Web API for portfolio analysis and optimization.
 
 ## CSharp