Frax (FRAX) — Complete Guide

FRAX is the original fractional-algorithmic stablecoin, launched by Frax Finance in December 2020. It pioneered the hybrid model: partially backed by USDC and partially by the algorithmic FXS token. Over time, Frax Finance has evolved toward near-full collateralization and expanded into an entire ecosystem including frxETH (liquid staking), FPIS, and the Fraxtal L2. FRAX is now primarily collateralized via the Algorithmic Market Operations Controller (AMO).

FRAX v1 used a fractional reserve model where the collateral ratio (CR) started at 100% USDC and reduced algorithmically as demand grew. When CR was 85%, minting $1 of FRAX required $0.85 USDC + $0.15 worth of FXS (which was burned). When redeeming, $0.85 USDC was returned + $0.15 FXS was minted. Since 2022, Frax has pursued 100% CR through the AMO system, which deploys excess USDC into Curve, Convex, Aave, and other yield-generating protocols. The yield generated by these AMO positions funds the Frax ecosystem and helps defend the peg. Fraxtal L2 and frxETH have added new revenue streams.

• +Pioneer of fractional-algorithmic design — influenced UST, FRAX, and many successors
• +AMO system actively earns yield on collateral through Curve, Convex, and Aave deployments
• +Frax ecosystem extends to frxETH, sfrxETH, Fraxtal L2, and FPIS — creating network effects
• +Near 100% collateralization now vs. original fractional model — learned lessons from Terra
• +Deep Curve pool integration — Frax has some of the most liquid stablecoin AMM positions
• +Sam Kazemian's leadership has navigated multiple crises while maintaining innovation

• !FXS token still plays a role in the ecosystem — FXS price decline creates reflexive risk
• !AMO dependencies on Curve, Convex, and Aave mean Frax is exposed to those protocols' bugs
• !The transition from fractional to full collateral has been slow and creates market confusion