In what could potentially be seen as a sign of growing concern among investors about the health of consumer spending, the relative strength of credit card companies has eroded in recent weeks. Within the SIA S&P 100 Index Report, Capital One Financial (COF), for example, has been out of the green zone since March, peaked near the top of the yellow zone back in July, slipped back into the Red Unfavored Zone earlier this month. COF continues to drop down the rankings, finishing yesterday in 66th position, down 3 spots on the day and down 18 places in the last month.