The Colombo Stock Exchange (CSE) has announced the following changes in the S&P Sri Lanka 20 index constituents made by S&P Dow Jones Indices at the 2018 mid year index rebalance.
The exclusions and inclusions as announced by S&P Dow Jones Indices, effective from June 18, 2018 are: Ceylon Cold Stores PLC, Ceylon Tobacco Company PLC, Nestle Lanka PLC and Seylan Bank PLC.

The new inclusions are: Ceylinco Insurance PLC, Melstacorp PLC, Softlogic Holdings PLC and Vallibel One PLC.

The S&P SL 20 index includes the 20 largest companies by total market capitalization, listed on the CSE that meet minimum size, liquidity and financial viability thresholds. 

The constituents are weighted by float-adjusted market capitalization, subject to a single stock cap of 15 percent, which is employed to reduce single stock concentration. 

The S&P SL 20 index has been designed in accordance with international practices and standards. 
All stocks are classified according to the Global Industry Classification Standard (GICS), which was co-developed by S&P Dow Jones Indices and MSCI and is widely used by market participants throughout the world.

To be eligible for inclusion, a stock must have a minimum float-adjusted market capitalization of Rs.500 million, a six-month median daily value traded worth Rs.0.5 million, traded at least for 10 days of each month for the three months prior to the rebalancing reference date, and have a positive net income over the 12 months prior to the rebalancing reference date. 

A revision of the S&P SL 20 methodology in March 2017 established the practice of a semiannual rebalance of the index (previously conducted annually).

The rebalance of the index now takes place during the months of June and December each year. 
The revision also established the inclusion of non voting ordinary shares listed by the respective companies of the S&P SL 20 Index, provided that such shares meet relevant liquidity requirements.