Dozens of high-speed traders and others from Wall Street are helping the Pentagon study how hackers could unleash chaos in the U.S. financial system.

The Department of Defense’s research arm over the past year and a half has consulted executives at high-frequency trading firms and quantitative hedge funds, and people from exchanges and other financial companies, participants in the discussions said. Officials described the effort as an early-stage pilot project aimed at identifying market vulnerabilities.

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