Speaking to The Edge Singapore just before Ecosperity Week 2026, Tsui, a veteran of the finance industry with 24 years of experience, shared his insights on sustainable investing, including trends and outlook. He has been involved in sustainability investing since 2017, establishing and integrating environmental, social and governance (ESG) considerations into investment practice.
Tsui adds that the institutional investing space is following the trend on pragmatism, focusing on credible transition mandates over the last few years. His observations are backed up by data from other sources.
According to a study by the Asia Investor Group on Climate Change, institutional investors in Asia prioritised energy storage, renewables generation and renewables transmission as their top three climate solution investment opportunities in 2025. The survey also found that investor interest has also risen in these sub-sectors over the same period, with energy storage experiencing the largest increase, doubling to 82% in 2025 from 40% in 2023.
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Meanwhile, for the 12 months up to April 2026, revenues of green products and services grew at its fastest pace, or 5.3%, since 2022 and consequently, the market capitalisation of companies with green revenues has swelled to over US$10 trillion ($12.93 trillion), according to a report by the London Stock Exchange Group (LSEG). The publication also reveals that the energy equipment and energy generation sub-sectors, are the fastest-growing green sectors over the past three years, with CAGRs of 20% and 16% respectively.
US — an unexpected paragon of pragmatic sustainable investing?
Despite policy seesaws such as the joining and withdrawal from the Paris Agreement, the provision and then rolling back of clean energy incentives, and increased focus on domestic oil and gas production from renewables generation, Tsui believes that sustainable investing is still occurring in the US, but has evolved.
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According to the International Energy Agency, the US also remains the second-largest clean energy investor globally, with an annual investment of US$400 billion. Furthermore, LSEG found that US firms account for 27% of global green revenue, led by sectors such as energy management and efficiency, transport equipment and energy generation.
Illustrating the level of sustainable investing activity in the US is a proposed acquisition of Dominion Energy by NextEra Energy, the largest electric utility company in the world. Worth approximately US$67 billion, the deal would be the largest green merger and acquisition transaction on record and the fourth largest globally, creating a North American green energy behemoth.
“I think sustainable investing in the US is still happening but in a different way, in the sense that energy transition, energy infrastructure remain quite robust, and there have been a lot of good climate-related technologies companies in the US as well,” shares Tsui.
“So it’s not like they [US] are scaling back, or we’re seeing tremendous pullback on sustainable investing, but they are just becoming more pragmatic, more focused,” says Tsui.
Sustainable funds — dominant Europe, rising Asia
Tracking sustainable mutual funds, investment research house Morningstar found that sustainable fund assets rose to US$3.9 trillion by end-2025, a y-o-y increase of over 20%.
Holding more than 85% of fund assets, Europe is dominant in this space. Tsui explains this is the result of different perspectives on sustainable investing by each region. “You will have to understand that sustainable investing also comes with different policies, and also about how different regions are looking at sustainable investing as an approach,” says Tsui.
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While Europe is the market leader in the sustainable mutual fund space, Asia is “building” strong momentum, with eight out of 10 major Asian markets having already developed their taxonomies, notes Tsui. “Taxonomy is actually critical in driving capital flow, because once you get the taxonomy done, that’s how we set the framework, or how to set the rules,” he explains.
A sustainable finance taxonomy is a standardised classification system that defines which economic activities, assets, and projects are considered environmentally sustainable. It acts as a “green dictionary” for investors, regulators and companies to channel capital into net-zero transitions and prevent greenwashing.
As such, financial institutions can develop ESG-related products based on established taxanomies. “From a regulatory perspective, I think Asia is pretty much a region that is setting the pace,” says Tsui.
On Asian markets gaining traction, Tsui highlights Thailand as one of the top growth markets due to the Thai government providing incentives for investing in ESG funds. According to Morningstar, the Land of Smiles attracted more than US$450 million in fund inflows in the last quarter of 2025.
AI in sustainable investing
When asked about AI’s impact on sustainable investing, Tsui says that some sectors will benefit hugely from this new technology. These include healthcare which can utilise AI for diagnosis and data analysis; agriculture, where AI is harnessed to analyse how weather climates are affecting crop yield, among other uses to enhance food security; and in smart city development in energy efficiency management.
He also observes that the development of data centres for AI is driving clean energy investment. “Electrification is definitely one of the key themes on how AI is consuming energy and you will definitely need better energy infrastructure to make energy supply more stable and sustainable,” he says.
To Tsui, the world is choosing to invest in various energy infrastructure such as energy storage, smart grids and renewable energy because they expand capacity in a sustainable way.
Expanding investment analysis with ESG
While the green economy is booming overall, sustainable investing is more than just green products and solutions. Sustainable investing is also a “practice” that involves the integrating of ESG risks and opportunities into the investment decision-making process.
ESG integration is an “overlay” on conventional fundamental analysis, explains Tsui. He adds that it uses new types of financial data — based on ESG — to contribute to financial models. “So that will be giving a clearer kind of visibility on potential risks and their management,” he says.
Using an example, Tsui shines a light on the utility of ESG integration. As the climate changes, a company’s daily operations may be disrupted with increasing frequency due to more extreme weather events.
“It wasn’t much of a concern … a few decades ago because it doesn’t happen often, but when there’s an increasing number of shutdowns, that is hurting your operations and revenue,” says Tsui.
The way he sees it, businesses have to account for “severe” climate situations as part of resilience building. For businesses, this would entail additional capex and seeing other impacts on bottomlines, while investors would have to account for the financial impact of these climate risks in their analysis.
Misperceptions about sustainable investing
Tsui acknowledges that there have been misperceptions in the market that have created misunderstandings about sustainable investing, including overselling how ESG is helping investors to gain excess return.
“So this is the reason why we always tell people that when you’re comparing financial return in the near term, it doesn’t seem obvious that sustainable investing will give an obvious or significant return difference [versus conventional investing],” explains Tsui. “But if you’re looking at a longer-term perspective … [and] considering ESG integration by screening out poor ESG constituents in your index, it gives you an annualised, excess return of about 30 bps [basis points] over about seven years’ time.”
Sustainable investments are also exposed to the traditional factors affecting the market, with the renewable energy sector a good example. While the sector is growing, Tsui points out that it is still impacted by earnings, supply and demand, valuation and risk, among others. “So this is more on the financial return risk that is largely driven by the misperception of the definition,” he adds.
A third misconception of sustainable investing is what can be invested. Tsui explains that this is dependent on the regulatory frameworks and standards which could relate to nuclear weapons, tobacco and high-emitting sectors, among others.
As a European company, Amundi adheres to EU regulations. “There’s a lot of explicit explanations on what we cannot invest [in] through our minimum standard exclusion policies,” shares Tsui. “So after that minimum exclusion or standards that we employ, then it will be very much up to what the underlying strategy objectives are.”
“There’s a term called ‘do no harm’,” says Tsui, adding that ESG practice is essential for Amundi. “So this is a strong belief that if we do the right things in this sustainable related framework, which has been evolving over time, it could unlock long-term value.”
