Impax Asset Management Reports Q3 AUM Growth Despite Outflows from Environmental Markets Trust

Impax Q3 AUM update: assets under management climbed to £23.3 billion

Impax Asset Management has put out a solid-looking third quarter update, with assets under management, or AUM, rising to £23.291 billion at 30 June 2026. That is up 4.4% from £22.312 billion three months earlier.

At first glance, that is a good number. But the detail matters here: the rise was driven by investment performance, market movements and foreign exchange, not by clients piling in fresh money. In fact, the business still saw net outflows during the quarter.

Key Q3 2026 numbers | Figure
AUM at 31 March 2026 | £22.312 billion
AUM at 30 June 2026 | £23.291 billion
Quarter-on-quarter change | +4.4%
IEM plc net flows | £(754) million
Net flows excluding IEM plc | £(994) million
Total net flows | £(1.748) billion
Performance, market movement and FX | +£2.727 billion

Why Impax AUM grew despite £1.748 billion of net outflows

This is the central point in the RNS. Impax lost money on a net basis from client flows, but markets were strong enough to more than offset that. That pushed the total AUM number higher.

AUM is the money an asset manager oversees for clients, and it matters because management fees are usually based on that pool of assets. So a higher AUM number is generally helpful for revenue, even if the quality of that growth matters a lot.

In Impax’s case, the quarter breaks down like this:

Total net outflows: £1.748 billion

Positive performance, market movement and FX: £2.727 billion

Net increase in AUM: roughly £979 million

That is a decent quarter on the surface, but it is not a perfect one. Market-led growth is useful, but flow-led growth is usually a stronger sign because it shows clients are actively choosing to hand over more money.

Impax listed equities carried the quarter, while fixed income stayed steady

The big driver of the AUM rise was listed equities. That part of the business rose from £19.342 billion to £20.317 billion, despite heavy outflows.

Fixed income was stable and slightly higher, moving from £2.329 billion to £2.341 billion. Private markets edged down from £641 million to £632 million.

AUM by asset class | 31 March 2026 | 30 June 2026
Listed equities | £19.342 billion | £20.317 billion
Fixed income | £2.329 billion | £2.341 billion
Private markets | £641 million | £632 million
Total firm AUM | £22.312 billion | £23.291 billion

The listed equities number tells you where the action is. It is both the largest part of the business and the part most exposed to market swings, which means strong equity markets can do a lot of heavy lifting.

Impax net flows are still negative, but the outflow story is improving

This is where management is trying to draw a line between bad outflows and less worrying outflows. Chief Executive Ian Simm says the net flows picture has improved once you exclude the one-off effect of the Exit Tender process by Impax Environmental Markets plc.

That one item accounted for 43% of total net outflows in the quarter. In cash terms, the RNS shows £754 million of outflows tied to IEM plc, against total net outflows of £1.748 billion.

That matters because one-off events do not always tell you much about the day-to-day health of the core asset management franchise. If a large chunk of withdrawals came from an anticipated event, investors can reasonably take some comfort from that.

Still, let’s not over-polish it. Even excluding IEM plc, Impax reported £994 million of net outflows. So this was not a return to net inflows, and the RNS does not disclose a full turnaround yet.

Ian Simm’s update on fund performance and distribution is the most encouraging part

The strongest read-across from the statement is that investment performance appears to be holding up well. Ian Simm said the firm’s thematic equities, systematic equities and fixed income strategies have remained strong since the start of the calendar year, with most outperforming relevant indices.

That is important because good performance tends to support future sales. Asset managers can survive a rough patch in flows if performance is strong enough, but it is much harder to win money when returns are lagging.

Management also pointed to an improving trend in flows via its largest distribution partner, with increased interest in its thematic equities range. The name of that partner is not disclosed, and the exact flow figures are not disclosed either, so investors should treat that as encouraging commentary rather than hard evidence.

Impax UCITS launch plans show demand in systematic equities is spreading to Europe

Another notable line in the update is the plan to launch its first UCITS product in systematic equities in Europe later this year. UCITS is a widely used regulated fund structure in Europe, designed to be easier to distribute across multiple markets.

That tells you two things. First, Impax says its systematic equities funds in the U.S. received net inflows during the quarter. Second, the company believes there is enough client demand in Europe to justify building out that product set.

The RNS does not disclose the planned launch date beyond “later this year”, and it does not disclose expected assets or fee margins. Even so, it is a useful strategic signal: Impax is not just defending the current business, it is trying to open another growth lane.

What this Impax RNS means for retail investors and shareholders

My take is fairly balanced. This was a good AUM update, but not a flawless one.

The positives are clear. AUM is higher, investment performance sounds strong, most strategies are said to be outperforming, and management is talking about better momentum with a major distribution partner. The planned UCITS launch also suggests confidence in demand for systematic equities.

The negatives are just as real. Net flows were still negative, and they were negative by a meaningful amount. Even after stripping out the IEM plc effect, there is still work to do before Impax can claim that client demand has fully turned the corner.

For shareholders, the biggest practical point is this: higher AUM supports fee income, but flows tell you more about future durability. If market performance cools off, Impax will want those improving sales trends to turn into actual net inflows.

So, the short version is simple. Impax had a stronger quarter than the outflow headlines alone suggest, thanks to market gains and solid fund performance. But the next big test is whether that improving flow narrative turns into hard numbers in future updates.