The All Share Price Index closed up 0.5 percent (15.95 points) to end at 3,131.29, while the Milanka Index of more liquid stocks gained 0.65 percent (22.92 points) to close at 3,527.16, according to provisional stock exchange data.
Turnover was 1.9 billion rupees.
"Today's turnover levels were dominated by the banking sector mainly Hatton National Bank (HNB) and Commercial Bank," Nikita Tissera, research manager at stock brokering firm, SC Securities said.
"Investors are buying into the banking sector ahead of earnings, hoping for better news in terms of asset quality."
Conglomerate John Keells Holdings closed at 154.00 rupees, up 25 cents, while index heavy Distilleries Company of Sri Lanka closed at 99.75 rupees, up 7.50 with 203,300 shares traded.
In off-the-floor deal, over three million HNB shares changed hands today. Brokers said there was market speculation, Browns & Company had sold.
Commercial Bank of Ceylon closed at 186.00 rupees, up 5.75 with over one million shares changing hands, while Hatton National Bank closed at 173.75, up 75 cents.
Sri Lanka's first ever closed-ended fund, NAMAL Acuity Venture Fund opened today at 57 rupees. The fund traded between a low of 55.00 rupees and a high 70.00, to close at 55.75 rupees, with 40,000 units changing hands.
Retailer favorites Touchwood Investments closed at 91.50 rupees, up 50 cents, and Lanka Cement closed at 33.50 rupees, down 50 cents.
Dialog Telekom, a unit of Telekom Malaysia closed at 7.75 rupees, down 25 cents, while fixed line operator Sri Lankan Telecom closed at 48.00 rupees, up 50 cents.