Update: No response from customer support yet. A support ticket was created Friday evening (it is now Tuesday afternoon).
Interestingly, my friend registered for Coinbase soon after I did. He also went through the "instant verification" process for his bank account information, but instead of purchasing a single BTC, he purchased five.
My friend's BTC order cleared without a hitch. The similarities between our purchase transactions include the following:
1) We both used instant verification for banking details
2) We both registered accounts, were verified, and made purchases all in our first day of site usage.
Differences between our purchase transactions include the following:
1) The BTC price increased significantly after my purchase (my purchase was cancelled) while BTC price remained relatively stagnant after my friend's purchase (his purchase was executed)
2) I purchased one BTC, my friend purchased five BTC
Possibly Coinbase uses the same heuristic that credit card companies use.
When credit card info is stolen, the thief usually doesn't make a big purchase as his first action, it draws too much attention. Instead, they do one or two very small test purchases at a gas station or drugstore, and if those go through ok, eventually they move to the big ticket item.
So perhaps, counterintuitively, people should only ever buy the
maximum BTC allowed on Coinbase, especially in their first few transactions, in order to avoid triggering their fraud detection algorithm.
Think like a thief who has just stolen someone else's bank account...and then do the opposite.
