Technology exists to show the actual short volume EVERY day, yet the SEC has them post it only twice a month. This is obviously not to the investor's advantage, because it allows the shorts to play games with the bi-monthly short interest. Close your short position ahead of the date of record, then re-short it so that the trade closes as per regulations 3 days later, and whammo ! ! ! Your trade is out there in cyberspace, your short exists but is not closed, so it doesn't show up as short interest.

That would be a good reason for some of these "wash trades" that Alan refers to -- they are trades at exactly the same price, with the same number of shares. Close one short, then re-open it so that you can manipulate the short interest figures.

If they had to report the short interest every day they couldn't get away with that. But golly, the SEC doesn't think that is necessary. I wonder why.