Namebase is an exchange registered based in San Francisco. To be more precise, Namebase is an onramp for Handshake and you can use its platform for buying and selling Handshake coins (HNS) as well as bidding on, purchasing, selling, and using Handshake names. The platform also supports Bitcoin.
The exchange was closed in 2019 with the preliminary notice informing about suspension of trading and deposit. Withdrawals had been operational for a couple of months since that time till December 1, 2019. The team explained the termination of activity by business reasons.