Why utility stocks trade like bonds when interest rates move

Electric and water utilities are often described as the ultimate defensive stocks. Whether the economy is booming or in a recession, households still turn on the lights, run their refrigerators, and heat their homes. Yet despite having some of the most predictable revenues in the stock market, utility companies like NextEra Energy (NEE) can experience sharp share-price swings whenever the Federal Reserve changes interest rates.

To understand why a power company reacts so strongly to the bond market, it helps to examine how utilities earn their money and how they pay for the massive infrastructure required to keep the grid running.

The regulated monopoly bargain

Building two sets of power lines down every residential street would be wasteful and unsightly, so local governments grant traditional electric utilities—such as NextEra Energy’s Florida Power & Light subsidiary—a legal monopoly over a specific service territory. In exchange for having no direct competitors, the utility gives up the right to set its own prices.

Instead, state public utility commissions regulate what the company can charge customers through a formula centered on its rate base and an allowed return on equity (ROE). The rate base is the total value of the physical assets the utility has built to serve the public: power plants, transmission towers, substations, and smart meters.

If a regulator grants a utility an allowed ROE of around 10%, the company is permitted to set electricity prices high enough to recover its operating costs, taxes, and interest expenses, plus earn roughly a 10% profit on the equity invested in its infrastructure. Consequently, the main way a regulated utility grows its earnings is by investing billions of dollars to expand and modernize its grid, thereby enlarging its rate base.

The double impact of interest rates

Because utilities pay out a large portion of their steady profits to shareholders as quarterly dividends—and because upgrading power grids and building wind, solar, and natural gas plants costs vast sums of money upfront—utilities rarely fund their construction budgets from cash flow alone. They borrow heavily by issuing long-term corporate bonds.

• Yield competition: Many retirees and income-focused investors buy utility stocks specifically for their dividend yields. When interest rates are near zero, a 3% or 4% dividend yield from a reliable utility looks very attractive. However, if US Treasury bonds and money-market funds start paying 4% or 5% with zero stock-market risk, investors often sell utility shares and move cash into bonds, pushing utility stock prices down until their dividend yields look competitive again.
• Higher financing costs: When interest rates climb, rolling over old debt or borrowing fresh capital to build new solar farms and transmission lines becomes more expensive. Unless regulators allow the utility to pass those higher interest costs on to consumers quickly, higher debt payments eat directly into corporate profits.

Regulated grids vs. competitive renewable energy

Not every part of a modern utility is strictly regulated. NextEra Energy, for example, combines one of America’s largest regulated electric utilities in Florida with an enormous competitive clean-energy arm, NextEra Energy Resources. This second division builds wind, solar, and battery-storage projects across North America and sells the electricity to other utilities and corporations—such as technology firms powering data centers—under long-term contracts called power purchase agreements (PPAs).

When evaluating a utility stock, investors check the balance between stable regulated earnings and faster-growing contracted projects. They also monitor the company’s credit rating, the growth of the population in its service territory, and the direction of long-term bond yields.