How traders might exploit quantum computing

If you had a sports almanac from the future as did Biff Tannen, the brutish bully of the time-travelling Back to the Future movie trilogy, how might you be inclined to take advantage of the foresight buried within it?

The obvious temptation would be to place sure bets in the market that make you rich. In Biff’s case, the wealth is then used to change the world into a dystopian reality in which he himself exists as “America’s greatest living hero”.

That sort of thing used to be considered fiction. But the dawn of so-called “supremacy” of quantum computing over conventional technology raises the possibility that one day soon someone might be able to effectively see into the future.

This is because quantum computers, when they become fully capable, are likely to be uniquely good at crunching probability scenarios. They are based on the mysterious world of quantum physics. Quantum bits or qubits are the basic units of information in quantum computers. Unlike the binary bits of traditional computing, which must be either zero or one, qubits can be both at the same time.

This gives quantum computers super powers that will allow them to solve probability-based tasks that would previously have been impossibly hard for conventional counterparts in realistic timeframes. If the problem at hand was a game of football, adding quantum computers to the mix is like allowing footballers to use their hands to get the ball into the net, say quantum experts.

It’s a prospect that poses an entire new set of challenges for market regulators and participants. If super quantum computers really can help institutions see into the future, the information advantage will be unprecedented.

It might also represent an entirely new type of front-running and market manipulation risk, one that regulators can’t necessarily even identify unless they too have a quantum computer at hand.

In Back to the Future, the almanac gave Biff a 60-year insight advantage over everyone else in his home 1955 timeline. With quantum computers, the edge might only be nanoseconds. But in the fast and furious world of high-frequency trading, that could be enough to sweep up.

The reassuring news — at least for now — is that we’re still at least five years away from quantum computers being powerful enough to compete with existing supercomputers on much simpler problems. Prediction might not even be their initial forte.

Goldman Sachs research recently noted, as and when quantum computers are rolled out, they are far more likely to be deployed on crunching options pricing conundrums or running Monte Carlo simulations that value existing portfolios than they are on predicting future movements of asset classes.

According to Tristan Fletcher, of artificial intelligence-forecasting start-up ChAI, that’s because prediction is ultimately about solving a very specific, deep problem by understanding the nuances of the data that matters.

“We are already at the limits of what any system that isn’t actually listening to Opec meetings and five-year plans is capable of,” he said. It’s not the complexity of the calculation that is the issue as much as the breadth of the data sample at hand. That means prediction wouldn’t necessarily get more accurate with quantum power.

The appeal to focus on “brute-force” problems such as optimising portfolio analysis or cracking cryptographic problems such as those that underpin bitcoin, the cryptocurrency, is far greater.

But this poses its own problems. If cryptographic systems can be broken, exceptionally sensitive data held across the financial system could be exposed and taken advantage of in unfair and market manipulative ways.

Rather than being able to better predict the market, the true pay off in the arms race might lie in achieving quantum-level encryption-breaking capability and using it subtly to seize the information that can get a trader ahead. Experts say the chances someone is already up to this, however, are low. If quantum supremacy had been achieved, the news of it would leak pretty quickly.

“We don’t know what we don’t know,” said Jan Goetz, chief executive of IQM, a quantum computing builder. “But generally the community is very small so everyone knows what’s going on. The status quo is clear.”

Nonetheless, the financial sector seems to be waking up to this quantum computing issue. Many banks and institutions are introducing teams to think exclusively about how quantum computing will affect their business. How far ahead they are on making their systems quantum secure is harder to say. It’s a secretive issue. For now, most agree, the threat level is low, not least because — as the hacking of the Colonial pipeline shows — system security is low enough to ensure far cheaper and simpler ways to hijack digital systems.

izabella.kaminska@ft.com

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