Tortoise Midstream Energy Fund, Inc. is an investment management firm specializing in listed energy investments. Iinvests primarily in midstream energy equities that own and operate a network of pipeline and energy related logistical infrastructure assets with an emphasis on those that transport, gather, process and store natural gas and natural gas liquids. Its investment vehicles include closed-end funds, open-end funds, private funds, exchange-traded funds, and insurance portfolio. The company has expertise in energy, credit, direct lending, and sustainable infrastructure.