Duke Energy posts negative beta but lags S&P 500 returns over five years

Duke Energy (DUK) shares have exhibited an inverse relationship with the S&P 500 over the past year, a dynamic that has reduced portfolio volatility but resulted in lower total returns compared to the broader market index. The utility stock, which pays a 3.5% dividend yield, has moved against the general direction of the market, offering a stabilizing effect for investors holding diversified S&P 500 funds.

Over the twelve-month period ending October 23, 2026, Duke Energy recorded a beta of -0.31. This metric indicates that for every 1% shift in the S&P 500, Duke Energy moved approximately one-third of that distance in the opposite direction. On an average up day for the index, characterized by a 0.638% gain, a $10,000 position in Duke Energy lost roughly $18.70. Conversely, on an average down day of 0.597%, the same holding gained about $19.40. The correlation between daily price changes and the index stood at -0.23, reflecting a weak inverse relationship.

Despite this counter-cyclical behavior, Duke Energy’s individual price swings have been more pronounced than those of the index. The stock’s annualized volatility reached 16.6% over the past year, compared with 12.7% for the S&P 500. Over a longer five-year horizon ending October 23, 2026, the utility delivered an annualized return of 7.9% including dividends, trailing the S&P 500’s 12.5% gain. Duke Energy’s annual volatility over this five-year period was 18.1%, slightly higher than the index’s 17.0%. As a result, the stock’s risk-adjusted return, measured by dividing return by volatility, was 0.436, falling short of the index’s 0.735.

The inverse pattern observed in the last year contrasts with the longer-term trend, where Duke Energy’s daily moves ran slightly in tandem with the index, showing a correlation of 0.18 over five years. The company’s financial profile is heavily concentrated in its core business, with the Electric Utilities and Infrastructure segment accounting for $29.4 billion of its $32.2 billion in fiscal 2025 revenue. Approximately 91% of total revenue comes from electric utilities.

Management has outlined a growth strategy anchored by new demand from data centers. Duke Energy has signed electric service agreements totaling 7.8 gigawatts with data center customers, which include minimum take provisions that serve as the basis for its revenue projections. During its August fiscal Q2 2026 earnings call, executives reiterated their goal to increase earnings per share by 5% to 7% annually through 2030.

However, significant capital expenditure and high leverage present risks to this steady growth picture. The company is deploying more than $1 billion per month on its capital plan. Its total debt equals 94.7% of its market value, a substantial contrast to the S&P 500’s debt-to-market-value ratio of 19.4%. This high debt level amplifies the potential for larger price swings if market conditions shift adversely.

Investors holding concentrated positions in regulated power companies building for data center demand should note that adding Duke Energy increases exposure to that specific sector rather than diversifying into a new area. The volume of data center agreements signed by Duke Energy remains a key metric to monitor, with the company’s next report expected in November.