Reuters reports that Capital One (COF) said U.S. credit-card defaults rose marginally in August after four straight months of declines. The credit card issuer said it annualized net charge-off rate, which are debts the company doesn't think it will recover, for U.S. credit cards was 8.19 percent in August, from 8.13 percent in July. The report indicated that this news is a signal that more Americans may be having problems paying their debts. Capital One shares are up 0.03%, or $0.01, to $38.61.