Hackers have launched a sophisticated wave of attacks on Wall Street in recent days, targeting the information systems of major money management firms, according to sources familiar with the matter.

One source, who requested anonymity, revealed that Point72 Asset Management informed investors on Wednesday that the company had suffered a cyberattack. However, a preliminary assessment suggests no client data was stolen, and the hedge fund continues to investigate and evaluate the incident.

The sources also reported that during this assault, hackers attempted to breach the systems of other major hedge funds, including Two Sigma Investments and Citadel, as well as several private equity firms. The attacks employed a technique known as voice phishing, or vishing, where cybercriminals use technology to mimic voices in phone calls or text messages, tricking employees into revealing sensitive information or granting access.

Two Sigma, which manages $75 billion in assets, stated that it had thwarted attempts to access sensitive data. Representatives from Point72 and Citadel declined to comment on the incidents.