The tide of regulation of cryptocurrency and blockchain could be turning in the United States. Following comments by newly-confirmed Treasury Secretary (and former Federal Reserve Chair) Janet Yellen describing Bitcoin as “inefficient” and “extremely volatile,” the price of the coin dropped 10% in 24 hours. During her confirmation hearings, Yellen described cryptocurrencies as a “particular concern” and signaled that the Treasury would begin examining blockchain-based financial networks. On the heels of Secretary Yellen’s comments, Congressman Patrick McHenry (R-NC), head of the House Financial Services Committee, and Congressman Stephen F. Lynch (D-MA), Chair of the Financial Technologies Task Force, introduced H.R. 1602, bipartisan legislation which directs the CFTC and the SEC to “jointly establish a digital asset working group” to “provide regulatory clarity” and to “create a critical collaboration [between the two agencies to] create fair and transparent markets.” Notably absent from this proposed collaboration is any mention of antitrust enforcement or involvement of the DOJ antitrust division or the FTC. However, recent comments by outgoing DOJ chair Makan Delrahim provide clues as to how antitrust may play a part in the regulatory framework for blockchain and cryptocurrency.