Abstarct: The Iranian cement industry has long been affected by mandatory price controls, government interventions, and suppressed profit margins, an approach that fostered operational inefficiencies and distribution rents. Since 2021, policymakers mandated cement supply on the Iran Mercantile Exchange (IME) to reform market structures and establish fair price discovery. This study evaluates the economic consequences of this structural shift by examining the impact of price control removal on the financial performance and idiosyncratic risk of cement companies listed on the Tehran Stock Exchange (TSE). Applying a purposive sampling method, 197 firm-year observations from 2018 to 2023 were analyzed. To control for inflation and isolate real growth from monetary illusion, the Consumer Price Index (CPI) was inherently incorporated as a macroeconomic control variable in the panel data regression model. Findings reveal that price deregulation significantly increased Real EPS and actual profitability, whereas ratio-baxsed metrics were largely absorbed by general economic inflation. Contrary to common assumptions, market transparency and deregulation led to a significant reduction in idiosyncratic risk, confirming the superiority of free-market mechanisms and the stabilizing role of the IME.