An increasing number of Americans have stopped paying their car loans, and Wall Street is starting to worry

Wall Street is starting to worry about the auto loan market.

Fitch, Moody's, Morgan Stanley, Mizuho and Evercore ISI have all published research on the market in the past few days, and there's a recurring theme: It's not looking good. There could be wide-ranging consequences, with automakers, the economy, consumers and one corner of the bond market all potentially taking a hit.

The increased interest in the auto loan market seems to be based on commentary from Ally Financial, weak guidance from Ford, and what Evercore called "a splurge in incentive spending."

• The delinquency rate for subprime auto loans is at the highest level in at least seven years.
• Banks are pulling back, and newer players with looser lending standards are stepping in.
• Used vehicle prices are dropping sharply, as the market is flooded with off-lease vehicles.
• The percentage of trade-ins with negative equity is at an all-time high.
• Asset-backed securities based on auto loans are showing signs of stress.
• A growing proportion of the auto loan ABS market is now made up of "deep subprime" deals.

To the charts: