Ha, ha! Who didn't see this coming? Chuck Grassley, apparently! Via TPM:

Early last year, Wall Street traders somehow found out that the Obama administration planned to make a policy change to Medicare before the news was even announced.The flurry of stock trades in major health care companies that followed has since caught the eye of federal law enforcement as well as Sen. Chuck Grassley (R-IA), who has made investigating the matter one of his pet projects on the Senate Finance and Judiciary committees. In his search, Grassley has gone as far as to cast suspicion on the Obama administration as the source of the leak.

But in a twist, the Wall Street Journal reported last week that federal regulators and law enforcement officials have now focused their attention on a Republican health policy staffer in the House. A lawsuit filed on Friday by the Securities and Exchange Commission, first reported by the Journal, said investigators believe the staffer "may have been" the source of the leak. It also sought to force the staffer to turn over records to investigators, something he and the committee have reportedly had refused to do despite being handed subpoenas.

The SEC lawsuit alleges that the House staffer, Brian Sutter, spoke with a lobbyist -- identifiedby the Journal as Mark Hayes, who happens to be a former aide to Grassley -- on the day of the leak. The suit alleges that Sutter was in touch with Hayes by both email and phone and that they discussed the upcoming Medicare policy change. Hayes then allegedly gave the information to a research firm, which distributed the flash that set off the trading, according to the SEC. A 2012 law, the Stop Trading on Congressional Knowledge Act, prohibits government officials from disclosing non-public information that could affect stock prices, the Wall Street Journal reported.

Grassley's office declined to comment to TPM about the latest development. He has also reportedly made inquiries into whether an aide to Sen. Orrin Hatch, his senior colleague on the Senate Finance Committee, had any role in the leak. Additionally, according to Politico, he has raised questions about Hayes’s role in the leaks. But the Obama administration appears to have been Grassley's initial and most public target when trying to identify the source of the leak.