Between commitment and deployment
LPs commit on day zero. Capital calls happen on a different schedule. The window between commitment and deployment routinely sits in 0.39%-yielding bank sweep accounts, while the rest of the institutional world earns 4.45% on equivalent-duration instruments.
On a typical mid-market fund with a long deployment curve, that annualized yield delta translates to material recoverable yield each year. The exact figure depends on fund size, idle share, and liquidity tolerance. Treasury reporting at this resolution requires dedicated headcount that mid-market sponsors typically do not staff internally.