Money market funds (MMFs) are generally considered safe investment vehicles, but the 2008 global financial crisis showed their vulnerability during market disruptions resulting in increased regulatory oversight across developed markets to protect investors. This paper examines the effect of MMF accounting regulation on investors in an emerging market context. It hypothesizes that the continued use of amortized cost methods to account for MMFs’ Net Asset Value (NAV) during market disruptions can result in unfair treatment of investors. The Egyptian money market provided a unique laboratory to test this hypothesis over a prominent economic crisis that combined high levels of interest rate volatility with a redemption-only structure for MMFs. A model that measures the discrepancies between the amortized and floating market NAVs per certificate for various money market portfolios (MMPs) simulating MMFs of different durations is tested using the Egyptian data. A sharp rise in interest rates is found to lead to significant discrepancies between the amortized NAV per certificate relative to their floating value. Serial investor redemptions of the certificates compound the discrepancies, but only certificate holders remaining in the funds bear the accumulated losses, which are augmented for portfolios with higher durations. The results suggest that emerging market regulators consider introducing the rules that switch to floating NAV calculations for MMFs during such periods to promote equality across all investors.