The SEC's point man on cryptocurrencies and initial coin offerings (ICOs) says that bitcoin and ether are not securities but that many, but not all, ICOs are securities and will come under the regulatory control of the SEC and relevant securities laws.

"Central to determining whether a security is being sold is how it is being sold and the reasonable expectations of purchasers," William Hinman, head of the Division of Corporation Finance at the SEC, said in a speech at the Yahoo All Markets Summit: Crypto conference in San Francisco.