A cash sweep is a feature that some investment accounts and financial products offer to help investors manage their cash holdings.
The basic idea behind a cash sweep is that any cash that is not immediately needed for investment purposes is automatically transferred, or "swept," into a separate account that offers a higher interest rate or other benefits.
Sweater places any uninvested capital into an interest-bearing money market account until it can be deployed into a portfolio company investment. This ensures your capital is never completely idle.