This study looks at how firms react to shocks in equity prices based on a classification which arises from social pressures rather than the financial objective of maximizing shareholders’ wealth. In order to meet the objective of the study, a sample of Malaysian firms from the period of 2003 to 2018 was utilized to evaluate the relationship between market and book debt ratios based on a social distinction. The study is based on the theoretical expectation that managers are inclined to adjust book debt ratios to converge with market debt values which arise from changes in equity values over time. We introduce a unique institutional setting into the relationship which is readily observable in the Malaysian capital market given the existence of Shari’ah and non-Shari’ah compliant company classifications on the stock exchange (Bursa Malaysia), as screened by the Securities Commission. The classification forms the basis for distinguishing Socially Responsible Investment options for investors. The findings reveal the existence of asymmetries in how both categories of firms adjust towards shocks in equity prices. The findings document that both compliant and non-compliant firms decrease book debt ratios in line with increases in firms’ equity values. Compliant firms, on the other hand, are more likely to increase book debt ratios during periods of decreases in equity values. Non-compliant firms do not significantly alter book debt ratios during periods of declining equity prices. The findings indicate that whilst firms tend to decrease debt levels in the presence of future growth potential, the response is asymmetric during periods of suppression of share prices. Thus, the screening of compliant versus non-compliant firms allows investors to distinguish sustainable firms in the long run, which further allows diversification when holding socially responsible investment portfolios. Our conclusions have wide reaching implications on a global scale for the development of sustainable capital markets.