"Variable net asset value": (VNAV). A variable net asset value per share money market fund. A money market fund which uses a mark to market basis to value some of its underlying portfolio of money market instruments. This results in a degree of variability in the investment values calculated and reported, as the market values of the underlying investments change. This method of accounting is contrasted with using an amortised cost basis of accounting for all of the investments, which is what Constant net asset value (CNAV) funds do.