As of June 2026, 62.53% is owned by Indian Promoters and 37.46% by Public.

Top five Promoters holding highest number of shares of Atmastco company are Subramaniam Swaminathan Iyer (73.04 lakhs shares / 27.92%), Bodies Corporate (48.33 lakhs shares / 18.47%), Apex Steel And Technology India Private Limited (44.65 lakhs shares / 17.07%), G Venkataraman (35.80 lakhs shares / 13.69%) and Jayasudha Iyer (3.82 lakhs shares / 1.46%).