For most lay investors, figuring out how to allocate money presents a dilemma. A dizzying maze of experts, investors, fund managers, and advisors exists to allow people to outsource their questions to a financial professional who can make responsible decisions on their behalf to grow savings. But to reliably figure out who won’t rip them off or make bad calls, regular people have to know so much that they could almost invest the money themselves in the first place.

Finance writers and others in the guidance-giving business offer some shortcuts to try to keep things simple. These range from the objectively good—making sure that the people in charge of money have an obligation to put clients’ interests first, without which they’re likely to look out for themselves and their employer—to the more dubious and superstitious-sounding. To wit: One famous old rule has it that clients looking to hand over their money should avoid advisors who drive flashy sports cars, since they’re likely to be risk-prone, unscrupulous, or both. Conversely, those with a practical, low-thrills car are said to perform better.

Turns out, this is one of those bits of folk wisdom that happens to be true. A group of researchers from NYU’s Stern School of Business, the University of Central Florida, the University of Florida’s Warrington College of Business Administration, and Singapore Management University set out to test it empirically, looking at a sample of 1,774 vehicles owned by 1,144 hedge-fund managers. Based on information that financiers are required by law to disclose to the government, he and his fellow researchers looked up publicly-available data on car purchases, and matched the hedge-funders to the autos. Sure enough, high-performance cars signal low-performance investors: The study finds that leadfoots make more trades, bring in smaller returns for clients, exhibit a greater volatility in the returns their investments earn per year, and are more likely to have been caught violating financial regulations.

The researchers, Stephen Brown, Yan Lu, Sugata Ray , and Melvyn Teo, began with a hypothesis about a psychological trait called “sensation seeking.” As they write, the trait is “defined by the seeking of varied, novel, complex, and intense sensations and experiences, and the willingness to take physical, social, legal, and financial risks for the sake of such experience.” Major sensation seekers, in other words, are the sort of people who probably make for good Hollywood protagonists, and they are more likely to step outside the law. Among other correlates established by earlier research, people with the trait are less careful with spending and engage in risky driving. So when their disposable incomes start to swell, the researchers reasoned, they are more likely to stop by a Ferrari showroom than a Subaru lot.

The study’s authors reason that hedge-fund managers make for perfect subjects for observing the upsides and downsides of being a sensation seeker, since they work in a relatively unconstrained sector of the finance industry, where personal tendencies towards risk and crime are less likely to be reined in by regulation or norms, as well as more likely to show up in investment-performance records and mandatory disclosures of past violations. But the researchers theorize that the same would be true of other finance professionals who make investment decisions, though it may be less pronounced.

It’s important to clarify that investing is inherently risky, and that there is such a thing as good risk, versus bad risk. For instance, if one can afford to, it’s rational to bet on a 50-50 chance that pays out more than double.

But the researchers found that the sports-car-driving managers are more likely to take bad risks; their higher-risk strategies don’t produce greater rewards. Quite the opposite, Brown and co. write:

We find that hedge fund managers who own powerful sports cars take on more investment risk. Conversely, managers who own practical but unexciting cars take on less investment risk. The incremental risk taking by performance car buyers does not translate to higher returns … In addition, performance car owners are more likely to terminate their funds, engage in fraudulent behavior, load up on non-index stocks ... and succumb to overconfidence.

The data show that the returns from investments made under hedge-fund managers who drive sports cars are about 17 percent more volatile than returns from ones who don’t have sports cars. These people trade in big sums; these numbers mean millions.

An even more instructive finding comes from the data on the correlation between car type and violations reported to the Securities and Exchange Commission (SEC). According to disclosures that traders are required to file with the government, sports-car owners are 17.3 percent more likely to have committed an SEC violation than are other car owners. On the other extreme, minivan drivers are a full 44.6 percent likelier than the rest to have a clean record. To be glib, fraudsters like roadsters.

One of the things the researchers worried could skew their results is the subjects’ possible biases towards particular car companies. If hedge-funders tend to buy a certain brand, and that brand happens to make lots of two-doors with high horsepower, then the results would reflect the automakers’ characteristics, not the investors’. The study contains an analysis of the data controlling for these potential brand-borne biases—say, against a dowdier automaker (like Volvo) or towards one could that makes lots of peppy sports cars (the paper mentions BMW, though Porsche is a more likely culprit). Yet the findings hold when controlling for this possible bias, among other potential confounding variables.

One quibble automotive enthusiasts may have with the study’s methodology is how it distinguishes between performance cars and non-performance cars. Like any good study, this one sets out an objective definition for the things it measures. But the way it defines performance cars, looking for two-doors with big power and torque numbers to see if they correlate with undesirable investing behavior, doesn’t map all that well on to the array of fast automotive offerings currently available to the hedge-fund managers of the world. Now happens to be a golden age for high performance four-doors. A decade ago, only the clunky and exotic Maserati Quattroporte filled a market niche that Porsche, Aston Martin, and even Dodge, with its Charger Hellcat, now compete in. So while “I know it when I see it” makes a bad legal definition of smut because it’s too subjective, it would be fascinating to see the study conducted based on a definition of “performance car” derived from polling the opinions of a group of automotive journalists and car obsessives. It seems likely the study’s results would be even more pronounced.

Still, regardless of exactly how the cars are categorized, the lesson is clear. Before putting their trust in financial professionals, consumers should find out what those professionals drive.