Short Term Trading Index

The Short Term Trading Index was invented over 30 years ago by Richard Arms and
is also known as ARMS Index. It is calculated by dividing advancing issues by declining
issues and advancing volume by declining volume. The first result is then divided by the
latter and the result is the TRIN. If the index is above one, the average volume of stocks
that fell on the NYSE was greater than the average volume of stocks that rose and vice
versa. But it is most confirmative when it reaches extremes. This indicator rises sharply
when the market is most depressed and selling is climaxing, and falls to very low levels
during buying frenzies.