An investment characterized by professional management of pooled funds is most likely a:

An investment characterized by professional management of pooled funds is best described as a pooled investment fund. This type of investment allows multiple investors to combine their resources into a single fund that is managed by a professional manager or management team. The manager's expertise is utilized to make investment decisions on behalf of the investors, who typically have limited control over the management of the fund but benefit from the collective investment strategies and potential diversification provided by pooling their resources.

Pooled investment funds can take various forms, such as mutual funds, exchange-traded funds (ETFs), and hedge funds. The central feature that defines them is the professional management and the pooling of capital from multiple investors to achieve investment objectives that might be difficult to accomplish individually.

In contrast, private equity investments usually involve direct investment in private companies or buyouts, often without the same level of liquidity or professional management available in pooled funds. Real estate investment trusts (REITs) do involve pooled investments and professional management focused on real estate, but they are specific to property investments and lack the broader application of pooled investment funds. Direct stock ownership involves an individual investor buying shares directly in companies, without any professional management applied to the overall investment strategy of an individual's portfolio.