Simply Put Its the Numbers of shares that are not delivered between MMs On a given day... You sell,,Someone buys,,,the shares must be delivered.. That is never completely done in one day...
What Reg Sho is Not...Is the short interest People betting a gainst a stock,,,thinking it will go lower You can check that at http://www.otcmarkets.com/home It is Hard to do (Short selling) and very expensive in the Pinks.. It is also the #1 EXCUSE for price decline and is total Bull Chit Dilution is the Number 1 real reason for Price decline That and simple profit taking,, as most pink plays last a matter of days or less the crowd sells off and moves to the next play
There are other reasons for Reg Sho Numbers New Paper or New shares being flooded into the market these have to be hand delivered on real paper and dat takes time
Here are some posts You may pay particular attention to Jim Bishops on Katx You may also remember,,that when you hear Naked Short Selling NSS Short selling, air shares etc..its an excuse for selling Either by the company, its financiers, Promoters or simple profit taking
also here is a quote from the SEC It addresses Naked short selling but applies
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The Sec and NSS
Investors should always be cautious that issuers, promoters, or shareholders may be seeking to stimulate buying interest by making false, misleading or unfounded statements in internet chat rooms or other such forums about alleged large naked short positions in some smaller issuers, particularly those trading on the OTCBB or Pink Sheets. Some individuals may encourage other investors to buy these issuers' securities by claiming that there will be an imminent "short squeeze," in which the alleged naked short sellers will be forced to cover open short positions at increasing prices. These claims in fact may be false.
On Katx Jim Bishop said it best and provided a link It's proof of nothing. A total of 5 million fails end of March considering the outstanding here, is diddly squat