Amid concerns about the proportion of dark trading in its equity markets, The European Securities and Markets Authority (ESMA) has launched a consultation to explore possible reforms to boost market transparency.

ESMA published a consultation paper that reviews the effects of its pre-trade transparency regime for equities, ETFs and other securities, which was first introduced in 2018.

“Market transparency is a key objective of [the trading rules] and, two years on from its inception, it is time to assess how transparency in equity and equity-like instruments has evolved,” said Steven Maijoor, chair of ESMA, in a statement.

Maijoor noted that the new requirements have been “partially successful,” but that regulators “also see some significant remaining challenges which should be tackled by a targeted review.”

Among other things, ESMA found that there hasn’t been a significant change in the share of trading volume that’s executed on trading venues, over-the-counter (OTC) and by systematic internalizers. It also found that found that a substantial share of the trading that’s executed on trading venues is still not subject to pre-trade reporting.

The regulator said that the central goal of its review and reform proposals is to simplify the existing trade-reporting regime and enhance overall trade transparency. For instance, ESMA is considering stricter requirements on pre-trade transparency exemptions, simplifying its oversight regime and introducing measures to discourage internalization.

“We believe that the proposals presented today will allow for a recalibration of [its trading rules], reducing its complexity, while improving transparency to the benefit of investor protection and orderly and stable markets in the European Union,” Maijoor said.

The deadline for the consultation is March 17.

ESMA said that it intends to submit its final reform recommendations to the European Commission by July. It will also be issuing a second consultation paper focusing on the bond and derivatives markets.