The All Share Price Index closed at 3,773.
55, up 4.74 points Monday, while the Milanka index of more liquid shares lost 0.27 percent (11.53 points) to close at 4,331.51.
Turnover was 1.0 billion rupees, according to stock exchange provisional figures.
Nikita Tissera, research manager at SC Securities, said investors sold blue chips and bought what they considered to be strategically important stocks like Richard Pieris and Maskeliya Plantations.
"Mid and smaller caps continued last week's positive momentum."
Brokers said 2.31 million shares of Richard Pieris and Company changed hands. It closed at 66.00 rupees, up 2.75.
Maskeliya Plantations closed at 33.75 rupees, up 3.50 with 1.77 million shares traded, brokers said.
Balangoda Plantations closed at 38.00 rupees, up 2.50, Hapugastenne Plantations closed at 42.50 rupees, up 1.00 and Horana Plantations closed at 30.
75 rupees, up 1.00.
Kelani Valley Plantations closed at 55.
00 rupees, down 1.25, Kotagala Plantations closed at 51.75 rupees, up 3.50 and Udapusselawa Plantations closed at 32.
00 rupees, down 1.50.
Commercial Bank of Ceylon closed at 193.75 rupees, up 3.75, Hatton National Bank closed at 176.
00 rupees, down 3.75, Sampath Bank closed at 228.50 rupees, down 50 cents and Seylan Bank closed at 43.
00 rupees, down 50 cents.
DFCC Bank closed flat at 177.00 rupees, and National Development Bank closed at 219.
25 rupees, up 1.25.
John Keells Holdings, a conglomerate closed at 169.
25 rupees, down 75 cents, and Distilleries Company of Sri Lanka, an alcohol producer closed flat at 117.00 rupees.
Diversified Hayleys closed flat at 209.00 rupees, Aitken Spence closed at 1,299.75 rupees and Hemas closed flat at 120.50 rupees, up 50 cents.
Environmental Resources Investments shares whose prices fluctuated last week, closed flat at 239.25 rupees. Its 0000 warrants closed at 146.50 rupees, down 2.50, and 0001 warrants closed at 145.
25 rupees, down 2.50.
Retailer favourites, Lanka Cement closed at 27.00 rupees, down 25 cents, and Touchwood Investments, a forestry company closed at 133.25 rupees, up 50 cents.
Sri Lanka Telecom, a fixed line operator closed flat at 40.00 rupees, and Dialog Telekom, a celco closed at 7.
00 rupees, down 25 cents.