I’m not sure how to interpret those numbers either, prc. Here is my guess.
For example, here is the REG SHO data for TRXBQ for April 8th.
Date|Symbol|ShortVolume|TotalVolume|Market
20100408|TRXBQ|67300|67540|O
The difference between the two reported numbers is 240. I personally bought more than 240 shares of TRXBQ that day (long).
It seems to me that the short volume number indicates ‘all short sale trades’, meaning short initiation (borrowing shares, either naked or not naked), and short position termination (selling shares, or covering). If it doesn’t indicate ‘all short sale trades’, and only indicates the number of shares for ‘short positions initiated’, then the number that is reported is incorrect since I purchased more than the 240 shares on 4/8.
If my guess is correct, and the short volume number indicates ‘all short sale trades’, then a large percentage of short volume could indicate a lot of short covering, which bodes well for longs (at least better than a lot of short initiations, I think).
Thoughts?