The Boardroom Coup: Shareholder Power Reshapes a Green Investment Giant

LONDON – June 17, 2026 – In a dramatic display of shareholder power, the entire board of Impax Environmental Markets PLC (IEM) has been removed and replaced following a decisive vote at a Requisitioned General Meeting. The move was orchestrated by the investment trust’s largest shareholder, Saba Capital Management, an activist hedge fund that has become an increasingly disruptive force in the UK’s famously traditional investment trust sector. Shareholders voted overwhelmingly—with approximately 71% of votes cast—to install Saba’s four independent director nominees, effectively handing control to the activist investor.

The outcome represents more than just a change in leadership; it is a stark referendum on performance and accountability. Boaz Weinstein, the founder and Chief Investment Officer of Saba, called it a “resounding rejection of the status quo.” In a statement following the vote, he declared, “The message is simple: the underperformance cannot go on.” The new board’s first and most urgent task, according to Saba, is to terminate the trust's contract with its long-standing manager, Impax Asset Management, and begin the search for a replacement.

A Reckoning Rooted in Red Ink

At the heart of this boardroom battle lies a simple, brutal fact: years of disappointing returns. While markets have surged, IEM investors have seen their holdings stagnate. Saba’s campaign was built on a foundation of damning statistics that the incumbent board could not easily refute. Over the last three years, IEM’s share price delivered a return of just 18.1%. During that same period, its own benchmark, the MSCI ACWI Index, soared by 66.5%—a staggering 48.4% performance gap.

The five-year picture is even more grim. An investment in IEM would have yielded a mere 6.2% return, while the benchmark grew by 82.6%. This chasm of underperformance, totaling 76.4%, became the central grievance for shareholders who felt their capital was being mismanaged.

The reasons for this lag are complex. The trust's focus on environmental markets—clean energy, water treatment, and waste technology—meant it largely missed out on the explosive, AI-driven rally that propelled mega-cap technology stocks and drove much of the MSCI ACWI’s recent growth. Furthermore, the broader thematic and ESG investing space has faced headwinds since 2022, grappling with higher interest rates and a political backlash that has cooled investor sentiment. Yet for shareholders, these contextual factors offered little comfort. The bottom line remained the bottom line, and the board was ultimately held responsible for failing to navigate the challenging environment.

The Activist's Blueprint for Disruption

This victory marks the ninth successful campaign for Saba Capital in the UK, solidifying its reputation as a formidable activist. Led by the quantitatively-driven Boaz Weinstein, Saba has developed a clear playbook: identify investment trusts trading at a significant discount to their Net Asset Value (NAV), build a substantial stake, and apply relentless pressure on the board to close that gap and unlock value for shareholders.

Saba’s tactics are aggressive, often culminating in requisitioning meetings to oust directors. The firm has been unafraid to challenge some of the biggest names in UK asset management, including Baillie Gifford and Janus Henderson. While not all of its campaigns have succeeded—it notably lost a series of proxy votes in early 2025—its wins are reshaping the governance landscape.

The outgoing IEM board attempted to characterize Saba as a “single minority shareholder” using its weight to seize control. Weinstein forcefully rejected this narrative. “We are not,” he stated. “Saba represents millions of ordinary savers who hold IEM through their investments with us. And we bought our shares from the very IEM shareholders the incumbents claim to champion – shareholders who felt compelled to sell after years of disastrous performance.” This framing recasts the activist as a champion of the retail investor, an agent of accountability rather than a mere corporate raider.

A Manager Under Siege

The immediate fallout from the vote lands squarely on Impax Asset Management, the specialist sustainable investment firm that has managed IEM since its inception. Saba has made it unequivocally clear that the new board’s first order of business must be to serve a termination notice. Losing the IEM mandate would be another significant blow for a firm already weathering a brutal storm.

Impax Asset Management has been hemorrhaging assets, with its assets under management (AUM) falling from £37.2 billion in September 2024 to just over £22 billion by March 2026. This includes nearly £13 billion in outflows over the last financial year, exacerbated by the loss of a major £5.2 billion mandate from St James Place. The firm's CEO, Ian Simm, has acknowledged that historical underperformance has weighed on sentiment, though he has also pointed to a recent strengthening in investment performance since the start of 2026. In an attempt to salvage a portion of the relationship, Impax is reportedly offering IEM shareholders the option to switch into an equivalent UCITS fund managed by the same team, but the board coup signals that a full separation is now the most likely path.

Governance at a Crossroads

The events at Impax Environmental Markets raise profound questions that extend far beyond this single trust. The outgoing chairman, Glen Suarez, lamented that Saba was able to gain control due to “peculiarities of the UK regulatory regime and UK company law.” His argument points to a structural vulnerability. In April, the IEM board offered an “Exit Tender Offer” that allowed shareholders to sell their shares at close to NAV. While intended as a constructive resolution, it had an unintended consequence: 80.5% of non-Saba shareholders took the exit, leaving Saba with a much larger proportional stake among the remaining investors and a clear path to victory at the general meeting.

The Association of Investment Companies has voiced concerns to regulators about this dynamic, highlighting the risk of a minority shareholder setting the direction of a trust against the wishes of the majority of its original investors. The situation at IEM is now a case study in how a determined activist can leverage market mechanisms and shareholder apathy to force radical change. As the new board at Impax Environmental Markets begins its work, the entire UK investment trust industry will be watching, wondering which underperforming board might be next in the crosshairs.