To some, a harbinger of the market can be found in short-term interest rates—as was evidenced in the United States when spikes in near-term rates ushered in an era of financial crisis.

Given that precedent, it looks like the Greek financial crisis is widening: The country’s 6-month yield is up to 6.60 percent; the gap in the 10-year yield between Greece and Germany is now the largest in the lifetime of the euro; money is moving out of Greece to global banks or off-shore; no firm deal has been reached on an aid package, and mass protests in the country over the debt crisis are gaining momentum. (Article continues below graph.)