The Colombo Bourse concluded the week on a positive note with a marginal gain, despite an initial decline on Monday, indicating a gradual regain of investor sentiment. The benchmark ASPI gained 18.89 points (+0.12%) while the more liquid S&P SL20 index was up by 32.14 points (+0.68%) to close at 15,879.33 and 4,766.57 respectively.