The company is engaged in discussions with the enforcement division of the U.S. Securities and Exchange Commission (SEC) and the United States Attorney's Office for the Southern District of New York, the regulatory filing said.
Block trading tends to increase during times of volatility as institutional investors rebalance their portfolios.
Broker-dealers frequently buy and sell blocks of shares, either on behalf of clients or as part of a hedging strategy, which are large enough to move a company's share price.
Still, the filing cautioned that there is no assurance that the investigations into the Wall Street firm's blocks business and sales and trading practices will be resolved.
The company disclosed in February that it was cooperating with U.S. regulators over those investigations.
