REUTERS/Brendan McDermid SEC chairman Jay Clayton weighed in on the crypto-mania sweeping Wall Street in a wide-ranging note Monday. Clayton warned investors about threats associated with cryptocurrencies and ICOs, a crypto-based fundraising method. Jay Clayton, the chairman of the US Securities and Exchange Committee, weighed in on the crypto-mania sweeping Wall Street in a statement Monday. "The world's social media platforms and financial markets are abuzz about cryptocurrencies and initial coin offerings," Clayton said.