As of September 2019, Coinbase does not support the trading of Skycoin (SKY). Skycoin is a decentralized cryptocurrency that uses a web-of-trust consensus model and is not based on blockchain technology.
We would like to caution against any claims that Skycoin is currently listed on Coinbase. There have been reports of scams and phishing attempts in which scammers falsely claim that Skycoin is available for purchase on Coinbase. We strongly advise against engaging in any activities related to these false claims. Please be aware that Coinbase does not currently support Skycoin, and any transactions related to Skycoin are not endorsed or supported by Coinbase. If you have questions about Skycoin or its availability, please visit the official website for more information.
Instead, Skycoin uses a data structure called a “blockchain” which allows for more flexibility and scalability.