In 2015, FINRA brought disciplinary proceedings against Scottsdale Capital Advisors Corporation and its principals, charging violations of FINRA Rule 2010 which requires that business be conducted with “high standards of commercial honor and just and equitable principles of trade.” The respondents sought to enjoin the FINRA proceeding in U.S. District Court, arguing that FINRA lacked authority to bring the disciplinary proceeding. FINRA, with strong support from the SEC, opposed the injunction, arguing, among other things, that the court lacked jurisdiction over the matter. The scope of FINRA’s authority matters to hedge fund managers because it affects brokerage transactions by funds, fund marketing and access to new issues. This article summarizes the regulatory and factual context of the litigation, the parties’ central arguments and the court’s ruling on the injunction. For coverage of other FINRA enforcement proceedings, see “Impact of Regulation SHO on the Short Sale Activity of Hedge Fund Managers and Broker-Dealers” (Nov. 10, 2011); “FINRA Fines Terra Nova $400,000 for Making Over $1 Million in Improper Soft Dollar Payments to Hedge Fund Managers” (Dec. 10, 2009); and “In FINRA’s First Action Involving Credit Default Swaps, FINRA Fines ICAP $2.8 Million to Settle Price Fixing Claims” (Jul. 16, 2009).