Robbins Geller Rudman & Dowd LLP said it is investigating potential violations of U.S. federal securities laws involving Cardinal Infrastructure Group Inc. (NASDAQ: CDNL). The investigation follows Cardinal Infrastructure’s Aug. 11, 2026, release of second-quarter results showing gross profit margin fell to 10.8% from 13.9% a year earlier. The company attributed adjusted gross profit margin pressure to increased subcontracted labor and equipment rental costs in certain developing markets, alongside customer demand and an intentional move toward a more diversified, less residential-weighted project mix. Cardinal Infrastructure’s stock fell more than 36% after the disclosure. Investors who incurred losses or have information relevant to the investigation can contact Robbins Geller or submit information through the firm’s website.