Al-Nuaimi SMO, Hamood MN. RISK-ADJUSTED PERFORMANCE EVALUATION OF INVESTMENT PORTFOLIOS USING THE INFORMATION RATIO AND TESTING THEIR EFFICIENCY: AN APPLIED ANALYTICAL STUDY OF A SAMPLE OF INVESTMENT FUNDS LISTED IN SOME GULF COOPERATION COUNCIL COUNTRIES. KSR [Internet]. 2026 Sep. 21 [cited 2026 Sep. 28];3(4):193-206. Available from: https://bulletin.ouk.kz/index.php/bulletin/article/view/112