Shares of NiSource experienced a sharp intraday decline, plummeting 5.10% on Wednesday as investors reacted to the utility company's second-quarter earnings report, which revealed a significant drop in profit driven by higher operating expenses and one-time costs.

The company reported a steep decline in net income, which fell to $45.5 million, or $0.09 per share, from $102.2 million, or $0.22 per share, a year earlier. The results were pressured by a 9.2% jump in operating expenses to $1.1 billion, including $21.4 million in costs tied to a labor lockout at its NIPSCO unit and $16.0 million in weather-related adjustments. While adjusted earnings of $0.16 per share met analyst expectations, they were down from $0.22 in the prior-year quarter, and underlying GAAP profitability deteriorated sharply.

The company reaffirmed its full-year 2026 adjusted earnings guidance of $2.02 to $2.07 per share and its long-term growth targets, but the quarterly profit slump and mounting cost pressures—including higher material costs driven by tariffs—overshadowed the outlook, fueling the sell-off during the session.