Capital One (COF), U.S. Bancorp (USB), BB&T (BBT) and Principal Financial Group (PFG) announce plans to raise capital and hope to pay back TARP loans. COF to sell 56M shares. USB to offer $2.5B in common stock. BB&T to sell $1.5B in shares. PFG to raise $1B in stock sales. Premarket: COF -8.2%. USB -4.9%. BBT -3.8%. PFG -7.2%.