Those are highs for both companies and better than what has been achieved by owners of apartments, which are also in demand but suffer somewhat from being overbuilt, said John Pawlowski, an analyst at the real-estate research firm Green Street Advisors.

“The rental market broadly is on very firm footing,” he said.

Created with Highcharts 6.0.4Rising RentsTotal return for single-family rental-home operators and the S&P 500, year to date.Source: FactSet

Some investors are skittish about the nascent single-family rental sector’s expenses. These include maintenance of tens of thousands of far-flung houses, as well as property taxes, which constitute roughly half of these companies’ ongoing costs and have been rising along with home values.

So far, though, demand for their family-size rentals in highly rated suburban school districts has been sufficient for the companies to be profitable […]