U.S. regulations require the stock markets to aggregate short positions. These two indicators and Market Scanner options are accurate, if all short sellers have made public their sales to the market or the stock market regulator .
Finally, the profession also uses the ratio of outstanding loan divided by the number of outstanding shares as an indirect indicator of the activity of selling, the latter being widely backed by a loan. This long or short ratio is published by the company Data Explorers.
The selling has almost everywhere a negative image. It is associated with speculation in the collective consciousness. Most countries with developed financial market have committed, from the summer of 2008 to impose restrictions on short selling. With hindsight, however, these measures remained defensible under a precautionary principle. Depriving the market of short selling could act as circuit breaker.