After a number of suspicious trades raised red flags about possible market manipulation or insider trading, Sen. Chris Coons, D-Delaware, joined a group of his Senate colleagues Oct. 22 in calling for federal authorities to investigate, protect U.S. financial markets and ensure no one is cashing in on material nonpublic information from the Trump administration, foreign nations or other entities.

Vanity Fair recently reported a mysterious trader or traders may have made more than $1 billion dollars in potential profits from suspicious market bets timed to e-mini S&P 500 futures trades and subsequent statements or actions from President Donald Trump regarding trade negotiations with China or from other actors with respect to other geopolitical events.

The group of senators is asking investigators and regulators to probe suspicious trading activity in U.S. financial markets to determine if any rules, laws or regulations were violated.

The senators sent a letter to the U.S. Department of Justice, Federal Bureau of Investigation, the Securities and Exchange Commission and the Commodity Futures Trading Commission calling for an investigation into whether there was wrongdoing, and if so, who is behind the potential windfall. The senators write “some may have an unfair trading advantage because of privileged access to nonpublic market-moving information potentially from government sources and, as a result, raise concerning questions about the integrity of our financial markets and our public institutions.”

In addition to Coons, the letter is also signed by Sens. Jack Reed, D-Rhode Island; Debbie Stabenow, D-Michigan; Sherrod Brown, D-Ohio; Robert Menendez, D-New Jersey; Dianne Feinstein, D-California; Chris Van Hollen, D-Maryland; Tammy Baldwin, D-Wisconsin; Ron Wyden, D-Oregon; Kirsten Gillibrand, D-New York; Catherine Cortez Masto, D-Nevada; Sheldon Whitehouse, D-Rhode Island; Ed Markey, D-Massachusetts; and Amy Klobuchar, D-Minnesota.