Just a word of advice, seems to be a problem among the few crypto'ers I know. When coinbase gets slammed and closes due to technical difficulties, its impossible to buy or sell anything online or via the mobile app. GDAX.com is directly linked to coinbase. All of your accounts are automatically linked with coinbase. Ive found out in times of technical difficulties with coinbase, gdax seems to still be reliable for access to your crypto's.
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From @edizzl79