The two sets of researchers have been examining when paying subscribers receive SEC filings compared with when they become available on the agency's website, the newspaper reported.
They found a wide variation in the lag time, from no delay to one lasting more than a minute. The ability to get the information before it is on the SEC website can give traders extra seconds to act on the news, WSJ said.
The studies focus on the SEC's Electronic Data Gathering, Analysis and Retrieval system, or Edgar, which is used to disseminate earnings reports and other documents filed to the regulator.
Representatives for the SEC were not immediately available to comment on the report outside regular U.S. business hours.
However, an SEC spokeswoman told the Journal that the agency has reviewed the working paper and was conducting a thorough assessment of the dissemination process to make necessary systems modifications.
A book by best-selling author Michael Lewis that asserted equities markets are rigged by high-frequency traders - who can dip in and out of markets in fractions of a second - triggered renewed regulatory scrutiny earlier this year.