What is MakerDAO's Peg Stabilization Module (PSM)?

Key Features & How the PSM Works

• 1:1 Stablecoin Swaps: The PSM enables anyone to exchange DAI for specific collateralized stablecoins (e.g., USDC) and vice versa. This direct swap mechanism acts as a highly efficient arbitrage tool, ensuring that the price of DAI can be quickly corrected if it drifts off its $1 peg.
• Minimal Fees, No Slippage: Unlike conventional DAI generation via overcollateralized vaults, the PSM charges little to no stability fee and essentially zero slippage, allowing instant arbitrage and scale as needed to maintain the peg32.
• Protocol-level Arbitrage: When DAI trades above $1, users can bring in stablecoins (like USDC), swap them for DAI using the PSM, and sell DAI at a profit—forcing the price down. When DAI is below $1, the flow reverses, supporting the price.
• Growing Influence in DAI Collateral: The PSM has become a dominant source of DAI minting, with a significant proportion of circulating DAI now backed by USDC through the PSM. This has allowed for rapid scaling and resilience of DAI, though it does introduce centralization risks34.

Variants and Upgrades

• LitePSM: MakerDAO has also launched LitePSM, a streamlined version focused on reducing user gas costs and supporting integrations with DEX aggregators like 1inch and Uniswap. LitePSM offers the same peg stabilization functionality in a more efficient package2.

Risks and Trade-offs

• Centralization Risk: While the PSM has greatly improved the robustness and scaling of the DAI peg, its heavy reliance on centralized stablecoins (mainly USDC) exposes DAI to risks associated with those third parties43.
• Resilience and Flexibility: However, by diversifying across multiple approved stablecoins and retaining decentralized collateral types (like ETH), MakerDAO balances efficiency, stability, and some degree of decentralization.

Summary Table: How the PSM Stabilizes the DAI Peg