# Usdc to Usds calculation in the Sky Strategy is slightly different than the Psm Usds Wrapper Low/Info · Three Sigma · Institutional lending · 26th November, 2024 Finding 3S-Maple-N09 of the Maple Cash Strategies security review. - Protocol: https://maple.finance/ - Report: /reports/maple-finance-iv - Source: https://cdn.sanity.io/files/qoqld077/staging/a68d604be9eca467b1f656c2ca775e1cebc2a468.pdf --- ### Description In the [psmWrapper](https://vscode.blockscan.com/ethereum/0xA188EEC8F81263234dA3622A406892F3D630f98c), the Usds amount from the gem is calculated as usdsInWad = gemAmt18 + gemAmt18 * psm.tout() / WAD; , but in the Sky Strategy it is calculated as (gemAmount_ * to18ConversionFactor * (WAD + tout)) / WAD; . ### Recommendation Although the result is the same (including the rounding error), consider implementing the same exact formula. ### Status Addressed in [#771a479](https://github.com/maple-labs/maple-strategies/pull/40/commits/771a479f860a3ad08511aa95e187e9baf96fc14d). --- Related findings: - [BatchOut:executeBatchWithdrawFromStrategyWithSwap() gives unfairly different slippage depending on the chosen token](https://0xsimao.com/findings/clip-finance-i-withdraw-unfairly-slippage-depending): Clip Finance Strategies