Relative Strength Index
by Peter Aan
Rules and Formulas: The formula for computing the Relative Strength Index (RSI) is well-known
and computerized by dozens of commercial software packages.
Briefly, to compute a 14-day RSI, you must first collect 14 days of closing prices. Looking at the daily
net changes (DNC) from the previous close, add all of the up DNCs and divide by 14 to get the up
average. Total the down DNCs and divide by 14 to get the down average.
Divide the average up DNC by the average down DNC. Add 1 to this result and divide the new result into
100. Subtract this figure from 100 to get the first RSI: