Rep. Chris Collins, R-N.Y., on Monday submitted his formal resignation to Speaker of the House Nancy Pelosi amid reports he will plead guilty to federal insider trading charges Tuesday.

Collins had pleaded not guilty in August 2018 to charges he shared non-public information related to Australian biotech firm Innate Immunotherapeutics with his family and friends. 

Collins had allegedly told his son, Cameron Collins, about a failed multiple-sclerosis drug trial in June 2017, with his son and other individuals trading the company's stock based on that information. The information went public days later and shares of Innate would fall 92%. 

Cameron Collins was also hit with insider trading charges in the case, along with Stephen Zarsky, the father of Cameron Collins' fiancee at the time. All three men have also been charged with lying to the FBI to cover up the scheme. 

Chris Collins, who represents some suburbs of Buffalo, was the first congressman to back Trump's 2016 presidential bid. After big election wins since 2012, Collins narrowly defeated his Democrat opponent in 2018. 

The troubles for Chris Collins come after Stop Trading on Congressional Knowledge Act (STOCK) was signed in 2012 by President Barack Obama. It combats insider trading by preventing members of Congress from using non-public information to profit on the stock market.

Before the STOCK Act was passed, insider trading was considered common in Congress, with some members having portfolios that performed better than hedge fund managers due to access to non-public information.