For algorithmic stabilization, a dual token model is used with SPA supply absorbing the price volatility of USDs. For minting USDs, the protocol collects eligible crypto-assets and SPA tokens. The crypto-assets are locked in the protocol as collateral and SPA tokens are burnt. While redeeming USDs, the protocol unlocks collateral and mints SPA. The elastic schedule of SPA supply helps contract or expand the fraction of USDs supply that is algorithmically stabilized.