The BLF considers sustainable development, including environmental, social, and corporate governance factors, during the investment process. The main reference indicators for new in-house investments in domestic stocks are as follows:

1. Received the National Sustainable Development Award from the Executive Yuan, the National Enterprises Environmental Protection Award from the Ministry of Environment, and the Occupational Safety and Health Award from the Occupational Safety and Health Administration, Ministry of Labor
2. Selected as a constituent stock of the TWSE RA Taiwan Employment Creation 99 Index, the TWSE RAFI® Taiwan High Compensation 100 Index, the FTSE4Good TIP Taiwan ESG Index, and the TIP Taiwan CSR SMC Index
3. Passed the Corporate Governance System Assessment organized by the Taiwan Corporate Governance Association
4. In the top 50% ranking in TWSE's Corporate Governance Evaluation
5. Signed collective bargaining agreements between labor and management

In addition, after the Labor Fund adopted the "TWSE RA Taiwan Employment Creation 99 Index" as the reference index for domestic mandates in 2011, it has continued to plan for the addition of new strategic indices as tracking indicators for domestic mandates. In 2014, the Fund adopted the "TWSE RAFI® Taiwan High Compensation 100 Index" as a tracking index for domestic mandates, guiding capital investment in constituent stocks with good investment returns, large salary scales, and high salary increases. Furthermore, the BLF adopted the "FTSE4Good TIP Taiwan ESG Index" and the "TIP Taiwan CSR SMC Index" in 2018 and 2020. This aims to implement the BLF investment principles of considering both profits and the sustainable development of companies in terms of environmental, social, and corporate governance factors.