diff --git a/readme.md b/readme.md
index c6e3bf6..f647fd6 100644
--- a/readme.md
+++ b/readme.md
@@ -99,6 +99,7 @@ Decentralized finance (#defi) is the movement that leverages open source softwar
   - [dYdX](https://dydx.exchange) ([source code](https://github.com/dydxprotocol/protocol_v1), [white paper](https://whitepaper.dydx.exchange/)) - Margin-trading and options protocols
   - [Gnosis](https://gnosis.io/) ([source code](https://github.com/gnosis), [white paper](https://gnosis.io/pdf/gnosis-whitepaper.pdf)) - Decentralized prediction market protocol
   - [Market](https://marketprotocol.io) ([source code](https://github.com/MARKETProtocol), [white paper](https://marketprotocol.io/assets/MARKET_Protocol-Whitepaper.pdf)) - Protocol for structuring peer-to-peer agreements that settle in the future based on the price of a reference asset
+  - [MCDEX](https://mcdex.io) ([source code](https://github.com/mcdexio)) - Decentralized Derivatives Exchange
   - [UMA](https://umaproject.org) ([source code](https://github.com/umaprotocol), [white paper](https://umaproject.org/UMA-whitepaper.pdf)) - Protocol that allows any two counterparties to design and create their own financial contracts that are secured with economic incentives alone, making them self-enforcing and "universally accessible"
   - [Veil](https://veil.co) ([source code](https://github.com/veilco)) - Peer-to-peer prediction market and derivatives platform built on top of Augur, 0x, and Ethereum