Deutsche Bank and UBS have joined the list of banks involved in an investigation into dark pools and high-frequency trading (HFT).
The move comes after Attorney General Eric Schneiderman of New York sued the British bank Barclays last month over the operation of its electronic trading division.
Both banks said that they are cooperating with the regulatory authorities with probes.
UBS disclosed that it was responding to inquiries about its dark pool and its order routing and execution practices from regulators including the Swiss domestic regulator, US Securities and Exchange Commission and the New York attorney general.
Deutsche Bank said that it has received requests for information from undisclosed regulators on high-frequency trading without elaborating.
UBS did not reveal the financial contribution of its dark pool and added that it is not material to overall results.
Additionally, Schneiderman’s office said to be looking at Credit Suisse over dark pools.
Credit Suisse CEO Brady Dougan said there has been a significant increase in inquiries on dark pools recently and the bank is supporting them.
Dougan said: "We don’t see any material impacts from that, but obviously that may develop over time."
UBS said: "These inquiries include an SEC investigation that began in early 2012 concerning features of UBS’s A.T.S., including certain order types and disclosure practices that were discontinued two years ago."
Recently, the New York Attorney General sued Barclays over allegations that it has dramatically increased the market share of its dark pool through a series of false statements to clients and investors about how, and for whose benefit, Barclays operates its dark pool.