My bank cut me off from buying from Coinbase with a credit card. When I asked why they told me it was their new policy as of the beginning of this month "to protect customer funds". I can't use the instant bank transfer because I'm not in the US and do not have a dollar account. Buying with a credit card makes a ton of sense because the purchase is instant. It's impossible to take advantage of a dip if your transfer takes several business days.