THIS IS NOT JUST AN AMERICAN OIL PROBLEM. Asian shares mixed as oil prices fall back; China cuts rate

“Almost by definition, crude oil has never fallen more than 100%, which is what happened today,” said Dave Ernsberger, global head of pricing and market insight at S&P Global Platts.

“I don’t think any of us can really believe what we saw today,” he said. “This kind of rewrites the economics of oil trading.”