I'll try. Banks have capital requirements. Some banks have more than they need, some have less. So essentially, the poor bank who needs cash borrows it overnight and then pays it right back to the rich bank with interest. This interest is paid by the Fed. And there's so much freaking money in the money supply, there is like over $2T of these arrangements on the Fed's books every night, so it's costing the Fed $650B daily in interest paid out to banks. The article points out the irony that the Fed is big time subsidizing the banks (subsidized anything is a problem for a free market) and because of their stupid interest rate policies combined with the massive money supply, the Fed is getting squeezed, hard. So yay, white hats winning the battle with the Federal Reserve! That's it, in a nutshell.