The Milanka index - which tracks the most liquid and highly capitalised stocks - gained a provisional 0.26 percent, or 6.08 percent, to 2,345.91 points.
Commercial Bank of Ceylon Limited gained 5.01 percent to 193.75 rupees a share on foreign and small investor buying.
"Commercial Bank is expected to announce strong third-quarter results," said one broker.
Shares of property developer Ceylinco Seylan Developments Ltd rose 11.54 percent to 7.25 rupees a share and Caltex Lubricants Lanka Ltd ended up by 3.16 percent at 73.50 rupees a share. Total market turnover was 391.0 million rupees with foreign purchases of 35 million rupees and 65 million rupees worth of foreign sales.