A venture fund is a 10-year pool of money. Limited Partners (LPs, the investors, pension funds, endowments, family offices) commit capital; the General Partner (GP, the VC firm) chooses the companies and runs the fund. LPs don't hand over the cash up front, the GP *calls* it down in instalments over the first few years as deals close. Early on the fund is underwater, paying fees and writing cheques with nothing exiting yet, which is why a plotted cash-flow line dips before it climbs: the famous J-curve.