Last Friday, at least 25% of trading volume in Facebook shares more than 143 million shares were short sales, according to data from exchanges that handled 94% of Facebook's total trading volume over the first four days.

WSJ: Some Facebook Underwriters Helped Short Sellers

The number of shares short is then compared to the average daily volume, in order to calculate the total number of trading days (at the average volume) it would take to close out all of the open short positions if every share traded represented a short position being closed.

FORBES: Connect

There was a bear raid on Bear Stearns starting March 10 that sent its stock plummeting 60% in the span of five days on trading volume that exceeded its total shares outstanding.

FORBES: Magazine Article

Total trading was the year's highest, with overall volume of New York Stock Exchange stocks exceeding 4.9 billion shares.

WSJ: Snap! There Goes Dow's Streak

Short interest accounts for more than 19% of the company's total float is 4.5 times the average daily trading volume of ESLR shares, indicating that ample sideline money exists to potentially push the security higher.

FORBES: Magazine Article

The London Stock Exchange, which says that algorithmic trading now accounts for about 40% of its total volume, is in the midst of a four-year project to develop such a platform by next year.

ECONOMIST: Technology and exchanges: Moving markets | The

The number of shares short is then compared to the average daily volume, in order to calculate the total number of trading days it would take to close out all of the open short positions if every share traded represented a short position being closed.

FORBES: Connect

This accumulation of pessimistic positions is nearly 11 times the stock's average daily trading volume and accounts for 25% of the company's total float.

FORBES: Options Watch