Many stockmarket technical analysts and chart watchers use the well known Relative Strength Index (RSI) as a reliable overbought/oversold indicator, but there are various other highly useful tools out there, and an excellent and simple one is the Williams Percent Range technical indicator. This was developed by Larry Williams, an expert in trading and systems analysis, and is a slightly different way of evaluating overbought and oversold market conditions. As with the RSI the %R always falls between a value of 100 and 0 (it is actually calculated as a negative figure in some software systems), and two horizontal lines can normally be defaulted to represent the -20% and -80% overbought and oversold levels. RSI watchers often use 30 and 70 a breast enlargement cream s the equivalent levels, but these are not set in stone for either indicator.The Williams %R formula The Williams %R indicator uses highs and lows within its calculation, so this is a bonus, and it is inverted by multiplying it by -100 to give the low and high figures. The formula which is preset on most software systems is: ((Highest high value (High, Number of periods chosen) – Close)/(Highest high value (High, number of periods chosen) Lowest low value (Low, Number of periods chosen))) * -100 Williams’ original analysis focused on 10 trading days as the number of periods chosen to determine a market’s trading range, and then the calculation was made by reference to where the current days closing price fell within that range.