Robinhood Markets Inc. is cooperating with an investigation from New York’s top law enforcement office into “brokerage execution quality,” the retail trading firm said in a regulatory filing.

Representatives for Robinhood and the New York Attorney General’s office didn’t immediately respond to messages seeking comment.

The online brokerage has faced heightened regulatory scrutiny during the past several years. In March 2020, several service outages prevented its customers from trading. Then, in early 2021, the so-called meme-stock frenzy spurred the brokerage to restrict trading.

US financial watchdogs have also taken a more aggressive approach to policing cryptocurrency after the collapse of FTX Trading Ltd, once one of the world’s largest crypto exchanges.

Robinhood said in the Thursday filing that it’s paid about $175 million in the past few years to to resolve actions brought by the Securities and Exchange Commission, the Financial Industry Regulatory Authority and several state regulators.

“The securities industry is highly regulated and many aspects of our business involve substantial risk of liability,” Robinhood said in the filing, adding that those risks include class-action lawsuits and regulatory actions.

In May, Robinhood said the SEC and FINRA were investigating employees’ use of “off-channel communications,” and in February the brokerage said it was subpoenaed by the SEC and California Attorney General’s Office for records tied to its cryptocurrency business.