Eos Energy Enterprises EOSE Insider Ownership

Updated Oct 10, 2026

In the last 12 months, insiders at Eos Energy Enterprises made open-market purchases of $751,662 (130.15K shares) and open-market sales of $18.03 million (1.78Mn shares).

• Counted by insider, open-market buying of EOSE stock in the past 12 months came from 4 insiders and selling from 8 insiders.
• Among Eos Energy Enterprises insiders, Joe Mastrangelo (Chief Executive Officer) led open-market buying over the past 12 months with $502,262 of purchases (83.9K shares); the latest was on March 4, 2026.
• On the selling side, Russell Monoki Stidolph (Director) was the top open-market seller of Eos Energy Enterprises over the past 12 months, with $11.47 million sold (766.13K shares) and the latest sale on December 8, 2025.
• Eos Energy Enterprises' latest insider trade on the open market was a sale of 250K shares for $980,000 by Joe Mastrangelo (Chief Executive Officer) on September 16, 2026.
• Outside the open market, Eos Energy Enterprises insiders received 523.11K shares in stock awards, acquired 2.55Mn shares through option exercises and conversions, gave up 393.54K shares to cover taxes or exercise prices and gave away 91K shares as gifts over the past 12 months.
• According to Business Quant data, insiders at Eos Energy Enterprises reported 7.3Mn shares in total in their latest Form 4 filings, up 16.61% from 6.26Mn shares at the end of Q2 2026 and up 10.94% from 6.58Mn shares at the end of Q3 2025.
• Direct holdings account for 5.23Mn shares (71.71%) of EOSE's insider total, and indirect holdings through trusts, partnerships and family members for 2.06Mn shares (28.29%).
• Business Quant counts 15 insiders with holdings in Eos Energy Enterprises stock, among the officers, directors and 10% owners who have filed a Form 4 in the past two years.
• Eos Energy Enterprises' top three insider holders by shares held are Russell Monoki Stidolph (Director, 2.41Mn shares), Joe Mastrangelo (Chief Executive Officer, 2.31Mn shares) and Nathan Kroeker (Chief Commercial Officer, 887.53K shares).
• The largest insider, Russell Monoki Stidolph, holds 33.06% of EOSE's insider total.
• Institutional investors held 67.07% of Eos Energy Enterprises stock at the end of Q2 2026, while the latest Form 4 filings of its insiders account for about 2.15%; other investors, including the public, hold roughly 30.78%.
• In the past year, 18 insiders of Eos Energy Enterprises submitted 68 Form 4 filings reporting trades, awards or other transactions.
• The insider holdings and trades above for Eos Energy Enterprises reflect Form 4 filings through September 16, 2026.