LucidaDocumentation
Open Lucida

Vaults

Rounding and Dust

How smallest-unit arithmetic can create tiny residual balances.

Integer accounting

  • SOL. SOL settlement uses lamports.
  • USDC. USDC settlement uses native token base units.
  • No floating point settlement. On-chain settlement should be described with integer arithmetic, not floating point math.
  • Rounding. Share minting and redemption may round down to the smallest unit.
  • Dust. Excess smallest units may remain in the Vault and belong to the remaining shares.
  • Final exit. The final user's exit should follow the actual on-chain implementation and attempt to settle remaining dust where supported, but Lucida should not promise that dust can never exist.