The Financial Industry Regulatory announced Monday it providing free public access to data on weeklytrades of individual stocks, exchange traded funds and other equities on each of the dark pools and other alternative trading systems at

Data on stocks in the S&P 500 Index, the Russell 1000 Index and some exchange traded products will be published on a two-week delayed basis. Information on all other National Market Service stocks and over-the-counter securities subject to Finra trade reporting requirements will be released two weeks later.

ATS trades account for over 30 percent of the total National Market System OTC share volume.

"Finra hopes that providing a clear view of the level of activity handled by these ATSs or 'dark pools' will increase market transparency and thereby enhance investor confidence. Finra's commitment to transparency is bringing light to what was previously a dark area of the equity markets. Making this information available to both the investing public and market participants provides an unprecedented view into the activity of these highly significant trading venues," said Steven Joachim, Finra executive vice president of transparency services.