Driehaus Capital Management purchased 7.70 million shares of Eos Energy Enterprises in the fourth quarter, worth an estimated $110.72 million based on quarterly average pricing, according to a February 17, 2026 SEC filing. The investment increased Driehaus' total stake to 14.27 million shares. Eos Energy, which manufactures grid-scale battery storage systems, has seen shares rise nearly 50% over the past year to $6.12, outperforming the S&P 500's 19% gain. Revenue reached $114.2 million in 2025, more than seven times the prior year, driven by increased deliveries and manufacturing improvements. The company reported a $701.5 million backlog and $23.6 billion commercial pipeline. However, shares have tumbled 47% since last quarter following softer-than-expected revenue guidance, partially reversing recent gains.

Eos Energy Enterprises faces a securities fraud class action lawsuit after its stock fell 39% on 26 February 2026. The lawsuit, filed in the US District Court for the District of New Jersey, alleges the company misrepresented near-term revenue growth and manufacturing capabilities. Eos Energy, which manufactures zinc-based battery energy storage systems, had guided fiscal year 2025 revenue of $150 million to $160 million whilst touting manufacturing progress. However, the company reported a $970 million net loss and missed guidance due to production inefficiencies, battery line downtime and quality delays. The complaint alleges violations of the Securities Exchange Act. Investors have until 5 May 2026 to apply to lead the case. Law firm Bleichmar Fonti & Auld is representing plaintiffs on a contingency basis.

A securities class action lawsuit has been filed against Eos Energy Enterprises, Inc. (NASDAQ: EOSE) on behalf of investors who purchased securities between 5 November 2025 and 26 February 2026. Law firm Robbins LLP is investigating allegations that the battery manufacturer misled investors about its business prospects. The complaint alleges Eos Energy failed to disclose production difficulties, including battery line downtime exceeding industry norms and delays in automated bipolar production quality targets. On 26 February 2026, the company reported full-year 2025 revenue of $114.2 million, significantly below its guidance of $150 million to $160 million, alongside a net loss of $969.6 million. Following the announcement, Eos Energy's share price fell 39.4% to $6.74. Shareholders may participate in the class action through Robbins LLP.