(49)In the context of deepening the CMU, the understanding of what constitutes instruments with a long-term economic profile is broad. Such instruments are non-transferable securities and therefore do not have access to the liquidity of secondary markets. They often require fixed term commitments which restrict their marketability and should be understood to include participation and debt instruments in, and loans provided to, non-listed undertakings. Non-listed undertakings include infrastructure projects, unlisted companies seeking growth, real estate or other assets that could be suitable for long-term investment purposes. Low-carbon and climate-resilient infrastructure projects are often non-listed assets and rely on long-term credits for project financing. Considering the long-term nature of their liabilities, PEPP providers are encouraged to allocate a sufficient part of their asset portfolio to sustainable investments in the real economy with long-term economic benefits, in particular to infrastructure projects and corporates.