Lay maintained his faith through no fewer than 14 margin calls that he had to meet by selling Enron shares.

FORBES: Magazine Article

As this article notes, after McClendon had to sell 94 percent of his Chesapeake shares because of those margin calls, he no longer held the equity stake that his prior employment agreement required.

FORBES: Chesapeake Energy: CEO McClendon Serves Himself First

They have no wish to be forced into joining a clearing house and thus into more demanding margin calls.

ECONOMIST: Derivatives: Over the counter, out of sight | The

This is an indication (and most certainly no more than only an indication) that someone, somewhere, is having to meet margin calls.

FORBES: Is John Paulson Having to Liquidate His Positions?