Turquoise Hill attributed the change to "[i]mproved rock mass information and geotechnical data modeling," which "confirmed that there are stability risks associated with components of the existing mine design." Turquoise Hill disclosed that the issues with the mine design were so unsettled that it would take until the second half of 2020 to develop a revised design for the mine. Following this news, Turquoise Hill's common share price closed at $0.60 per share, down 43.93% from the prior day's closing price of $1.07 per share, with over 50.2 million shares traded. On July 31, 2019, after the close of trading, Turquoise Hill issued a press release and Management Discussion & Analysis ("MD&A") making further disclosures about the status of the project, including that Turquoise Hill took a $600 million impairment charge and a substantial "deferred income tax recognition adjustment" tied to the Oyu Tolgoi project, and that it suffered a loss in the second quarter.