The U.K.’s Financial Conduct Authority (FCA) is considering a ban on some cryptocurrency-based derivatives, a senior executive has said. Speaking at an event in London covering the regulation of cryptocurrencies, Christopher Woolard, executive board member and director of strategy and competition at the FCA, said that the watchdog has concerns that retail investors are being sold “complex, volatile and often leveraged derivatives products” based on cryptocurrencies with “underlying market integrity issues.”