While stocks are understandably stealing the headlines in Monday’s nasty trading session — the Dow Jones Industrial Average DJIA, -0.87% dropped more than 2,000 points early — the real danger to the U.S. economy could ultimately come from the credit markets.

Holger Zschaepitz, a popular financial commentator and author of “Debt without atonement,” or “Schulden ohne Sühne,” tweeted out this illustration from Deutsche Bank economist Torsten Slok, calling it “one of the most dangerous charts in financial markets”: