How Your Personality Can Affect Your Portfolio

Can certain personality traits explain investors’ risk tolerance and investment decisions?

A forthcoming paper suggests it might. Specifically, the authors found that two personality traits—neuroticism and openness—significantly affect how investors perceive the economy, financial markets and their likelihood to buy stocks or stock funds, with those who are less neurotic and more open tending to have a higher allocation to equities.

While the authors primarily studied investors in the U.S., they also identified similar patterns among investors in Germany, Australia and China.

The Wall Street Journal spoke with two of the paper’s co-authors, Hongjun Yan, a professor of finance at DePaul University’s Driehaus College of Business, and Cameron Peng, an assistant professor of finance at the London School of Economics, about their findings. Zhengyang Jiang, an associate professor of finance at Northwestern University’s Kellogg School of Management, is the paper’s other co-author.

Here are edited excerpts of the conversation.

WSJ: How can psychology theories help to explain investor behaviour?

YAN: Investors often have very different portfolios. Traditionally, economists focus on risk aversion and market expectations, but in this paper we argue that well-known personality traits—extroversion, agreeableness, openness, conscientiousness and neuroticism—provide a new dimension to explain investors’ choices.

In the Winnie-the-Pooh stories, Tigger is always excited and optimistic while Eeyore is always down and pessimistic. You might expect their investment portfolios to look very different and reflect their overall outlook.

WSJ:How did you study this topic?

PENG: We collaborated with the American Association of Individual Investors, administering a survey to over 3,000 of its members. We collected information on their personality traits, market expectations, and investment decisions. The AAII sample is predominantly wealthy, white, older men. And when they make investment decisions, they are usually quite big, involving hundreds of thousands or even millions of dollars. Their actions can have a real impact on the market.

WSJ:What did you find?

YAN: We found that neuroticism and openness are correlated with investors’ beliefs about the market and their likelihood to buy equities. We were surprised that agreeableness wasn’t important when it comes to investment beliefs or decisions since other researchers have found that agreeableness tends to be correlated with other economic outcomes, like success in negotiating wages.

WSJ: How does neuroticism affect investors’ decisions?

YAN: Someone who is more neurotic has a very different outlook than someone who is not in terms of stock-market expectation. For example, an investor ranking in the middle of the [neurotic] scale might expect an annual stock-market premium of about 6%. But investors at the top of the scale are likely to only expect a 4% stock-market premium, while investors at the bottom of the neuroticism scale are likely to expect an 8% stock-market premium.

PENG: Neuroticism also affected how respondents invested their money in their actual accounts. More neurotic investors were less likely to own equities. Very neurotic investors invested about 56% of their portfolio in equities, while investors who weren’t neurotic invested about 64% of their portfolio in equities.

WSJ:How does openness affect investors’ decisions?

PENG: Investors ranking high for openness were more likely to entertain the possibility of extreme events, like a market crash or a run—really any scenario when the market goes up or down by more than 20%.

Investors who were very open were somewhat more likely to take risks by buying equities. Specifically, investors who were the most open were 3 percentage points more likely to own more equities than investors who weren’t. They had about 62% of their portfolio in equities, while investors who were less open had about 59% of their portfolio in equities.

WSJ: What did you find when you looked at data from other countries?

YAN: We find that neuroticism and openness affect market perceptions and decisions fairly consistently across different data sets. That’s quite remarkable considering the culture and investing environment in each country is very different.

WSJ:What are the study’s implications?

YAN: Personality traits may shape investors’ decisions in ways that many economists have yet to seriously consider. Our research, for instance, also suggests more extroverted and more neurotic investors’ investment choices could be highly influenced by social interactions, or what their friends or colleagues are doing. That insight goes beyond economists’ traditional framework, which focuses on risk tolerance and market expectations, and could help researchers better explain investor behaviour.

PENG: Large asset-management firms or financial planners could spend time getting to know their clients’ personalities and use those insights when they make investment recommendations. Maybe they could encourage investors who tend to be neurotic to be a little less pessimistic.

For decades, the world’s computing power has quietly expanded at an astonishing pace.

From the first transistor developed at Bell Labs in 1947 to modern processors containing billions and even trillions of transistors, each generation of technology has been faster, smaller and more powerful than the last.

But according to quantum physicist and technology entrepreneur David Reilly, that era of effortless progress is beginning to slow.

Reilly, CEO of Sydney-based Emergence Quantum and Professor of Physics at the University of Sydney, says the computing infrastructure underpinning modern economies is approaching fundamental physical limits.

And that could have enormous implications for finance, artificial intelligence and global investment.

Speaking at an industry event organised by Kanebridge International, Reilly said many critical parts of modern society depend on computing and the infrastructure used to process information.

The slowdown behind the tech boom

For years, the technology industry relied on a steady improvement known as Moore’s Law, where the number of transistors on a chip doubled roughly every two years.

More transistors meant more computing power, allowing faster software, smarter devices and ever-larger data systems.

Today, however, those gains are slowing.

“It feels to me very innate that I’m going to just find that next year there’s going to be another breakthrough,” Reilly said.

“But if you look at the data…there’s a slowing down, a roll off in performance that started some 10, 20 years ago.”

Rather than making chips dramatically faster, manufacturers are now largely increasing computing capacity by packing more transistors onto each processor.

The approach works, but it comes with growing complexity, higher costs and increasing energy demands.

The brute-force race for AI

That challenge is already visible in the massive data centres being built to support artificial intelligence.

In the race to dominate AI, companies are constructing vast computing facilities that consume huge amounts of electricity and water. Reilly described this expansion as a “brute force” approach driven by the global competition to develop advanced AI systems.

Yet the demand for computing power continues to accelerate.

Artificial intelligence, advanced robotics, healthcare research, pharmaceuticals and cybersecurity all require far more processing capacity than today’s systems can easily deliver.

The question now facing the technology sector is whether traditional computing can keep up.

Enter quantum computing

That is where quantum computing enters the conversation.

Unlike conventional computers, which process information using binary switches that represent ones and zeros, quantum computers exploit the unusual behaviour of particles at the atomic scale.

Reilly describes them as a fundamentally different type of machine.

“So a quantum computer is a wave computer,” he said.

Instead of processing information through simple on-off switches, quantum systems can use wave-like properties of particles to process many possible outcomes simultaneously.

Those waves can interact in complex ways, reinforcing correct solutions while cancelling out incorrect ones. In theory, this allows quantum systems to tackle certain types of problems dramatically faster than classical computers.

What it could mean for finance

The concept may sound abstract, but its potential applications are significant.

Quantum computers are expected to transform areas such as materials science, chemical modelling and pharmaceutical development.

They could also help solve complex optimisation problems in logistics, finance and risk management.

For financial institutions in particular, the technology could offer new tools for detecting fraud, analysing market behaviour and optimising portfolios.

But the shift will not happen overnight.

“One message to take away is that quantum is not going to suddenly solve all of your problems,” Reilly said.

Instead, he said quantum systems will likely complement existing computing technologies as part of a broader and more diverse computing ecosystem.

Why data centres may soon “go cold”

One key change already emerging is how computing systems are physically designed.

Many next-generation technologies, including quantum processors, operate far more efficiently at extremely low temperatures. As a result, future data centres may rely heavily on cryogenic cooling systems to manage heat and energy consumption.

Reilly believes that the shift will gradually reshape the computing industry.

“Over the next five years, you’re going to see data centres go cold,” he said.

“And as that happens, they almost drag with them new compute paradigms.”

Emergence Quantum, the company he co-founded, is focused on developing technologies to support that transition, including cryogenic electronics and integrated hardware platforms designed for quantum computing and energy-efficient systems.

A new technological era

For investors and businesses, the technology remains in its early stages. But the scale of global interest is growing rapidly.

Governments, research institutions and technology companies are investing heavily in quantum research, betting it could become a foundational technology for the next generation of computing.

For Reilly, the moment feels similar to earlier technological turning points.

In the 19th century, new discoveries in thermodynamics helped drive the development of steam engines and the Industrial Revolution. In the 20th century, advances in electromagnetism led to radio, television and eventually the internet.

Quantum physics, he suggests, could represent the next chapter in that story.

“Today we have, as a society, in our hands new physics that we’re just beginning to figure out what to do with,” Reilly said.

“But I think it’s an exciting time to be alive and watch what happens over the coming decades.”