When it comes to RELPs, "all real estate assets are fair game," says Blake. "Single-family homes, multi-family homes, retail, industrial, office, hospitality, land, you name it." Some RELPs invest in dozens of properties, some in only a few, or even one. Often, they specialize in a particular type of property — say, historic rehabs or office buildings. They might invest heavily in commercial property loans or mortgages, too.