The FIX Protocol: A Complete Guide for Trading Systems
How FIX messages are built, how sessions recover from gaps, which version to use, and where binary encodings like SBE and FIXP fit — a practitioner’s guide to the language of trading.
Trading Protocols & APIs
FIX, Nasdaq ITCH and OUCH, Simple Binary Encoding, CME MDP 3.0, NYSE Pillar, multicast market data and crypto exchange APIs.
Protocols & APIs: an overview
Protocols are the language between trading systems and venues. The choice between FIX and native binary protocols affects latency, reliability and engineering cost.
Our protocol guides explain message structures, session layers, recovery mechanisms and implementation pitfalls for the protocols institutional and HFT firms use every day.
Latest Protocols & APIs research
Browse all research Key concepts
- FIX
- The Financial Information eXchange protocol, the industry standard for order routing and execution messages.
- ITCH
- Nasdaq’s binary, order-by-order market data protocol that conveys full depth of book.
- SBE
- Simple Binary Encoding, a zero-copy message encoding designed for low-latency trading.
Research roadmap
What we cover in Protocols & APIs
Our editorial plan for this section. Published guides are linked; the rest are in research.
- Live The FIX Protocol: A Complete Guide for Trading Systems
- Soon How to Choose a FIX Engine: Build, Open Source or Buy
- Soon FIX API Trading for FX and Crypto: Practical Guide
- Soon Nasdaq TotalView-ITCH 5.0 Explained
- Soon How to Build a Low-Latency ITCH Feed Handler
- Soon The OUCH Protocol: Low-Latency Order Entry at Nasdaq
- Soon Simple Binary Encoding: How SBE Achieves Low Latency
- Soon CME MDP 3.0: Architecture, Messages and Book Building
- Soon NYSE Pillar: Order Entry and XDP Market Data
- Soon The FAST Protocol and Why Exchanges Moved Beyond It
- Soon How Multicast Market Data Distribution Works
- Soon FIX vs Native Binary Exchange Protocols
- Soon Eurex T7: Order Entry and Market Data for Low Latency
- Soon Choosing the Right Crypto Exchange API for Trading