NRG Energy Inc (NRG) shares tumbled 5.69% in pre-market trading on Wednesday following the release of its second-quarter 2025 financial results. The energy company's earnings slightly missed analyst expectations, and its full-year guidance came in below market estimates, sparking investor concerns.

For the second quarter, NRG reported non-GAAP earnings of $1.73 per diluted share, falling just short of the $1.74 expected by analysts surveyed by FactSet. While this represents a slight improvement from $1.70 a year earlier, it wasn't enough to impress investors. The company's revenue for the quarter ended June 30 was $6.74 billion, surpassing both the previous year's $6.66 billion and analyst expectations of $6.45 billion.

Despite the revenue beat, NRG posted a net loss of $104 million for the quarter. However, this marks a significant improvement from the same period last year, representing an $842 million reduction in losses. The company also reaffirmed its adjusted earnings guidance for fiscal 2025 of $6.75 to $7.75 per share, which falls below the $7.86 expected by analysts. This conservative outlook appears to be a key factor in the stock's pre-market decline. On a more positive note, NRG announced plans to return $1.3 billion to shareholders via share repurchases in 2025, which may help to mitigate some investor concerns in the long term.