Special Counsel Robert Mueller impaneled a grand jury in Washington, D.C., as part of his investigation into whether Russia interfered in the 2016 U.S. elections, according to an Aug. 3 report in The Wall Street Journal.
The Journal, citing two people familiar with the matter, said the grand jury had begun its work in recent weeks.
Reuters on Aug. 3 reported that grand jury subpoenas have been issued regarding a meeting in 2016 between Donald Trump Jr., the son of President Donald Trump, and a Russian lawyer.
The S&P 500 dropped 5 points directly following The Wall Street Journal report, though it regained some of that in late trading to close down 0.22% on the day.
A spokesman for Robert Mueller's office declined to comment on the Journal story. The White House and an attorney for Trump Jr. did not immediately respond to an email seeking comment. Trump Jr. has previously said he would be "happy to work with the [Senate Intelligence Committee] to pass on" what he knows.