The SEC this week charged online brokerage optionsXpress that specializes in options and futures as well as its former chief financial officer, three other optionsXpress officials and a customer with conducting “an abusive naked short selling scheme.”

optionsXpress, now a subsidiary of Charles Schwab Corp., said its trades were neither novel nor exotic. And not shams, as the SEC contends.

Here is a step by step rundown on how the SEC says the ‘scheme’ executed by optionsXpress, involved ‘naked’ short selling, with failure to deliver the securities involved in the trades.

Then, a step by step rundown of why optionsXpress contends it always delivered on its end of the trades.

Click here to run through the steps.