BT: Too high a proportion of your bank credit card accounts were opened recently.
Opening multiple bank credit cards in a relatively short period of time is a proven indicator of increased risk because the history on those new accounts is not long enough to provide sufficient payment and account information to demonstrate responsible behavior on those accounts. In addition, having multiple accounts that are relatively new is seen as a higher risk because of the possibility of becoming overextended, which can then lead to late payments or defaulting on the account.
Use your existing credit responsibly and make your payments on time. Your credit score will benefit as you make payments on time and manage the accounts in a responsible fashion. Manage your credit wisely by planning ahead for your credit needs so you can avoid applying for more credit than you need.