.
Tips on Technicals: The Directional Movement System
Williams %R
Williams %R is an overbought/oversold indicator developed by Larry Williams. In his original work, Williams examined ten trading days to determine the trading range, then calculated where today’s closing price fell within that range.
To calculate the %R, you must first detemine the highest high and lowest low for the length of the interval - this is the trading range for the specified interval. Once those values are determined, the general formula for the % R is as follows:
%Rt = ( (Highn-Closet) / (Highn - Lown) ) X 100
%Rt = the percent of the range for the current period
Highn = the highest price during the past n trading periods
Closet = the closing price for the current period
Lown = the lowest price during the past n trading periods
n = the length of the interval (we use 10 days)
Assume the market is Treasury Bills. The high for the past ten trading intervals is 9275 and the low is 9125. The closing price in the current period is 9267. If you substitute those values in the equation, you get:
%R = ( (9275-9267) / (9275-9125) ) X 100
= (8 / 150) X 100
= 5.33
Trading signals from Williams %R
This study attempts to use the market’s normal strength and weakness to forecast turns. Since it measures the current price relative to the trading range of the past 10-day period, it always attempts to sell strength and buy weakness.
The system attempts to measure overbought and oversold market conditions. The %R always falls between a value of -100 and 0. The trading rules are simple: When %R reaches -10% or lower, you sell; when it reaches -90% or higher, you buy.
Note that these values are reversed from normal thinking. The %R works best in trending markets, either bull or bear trends. Likewise, it is not uncommon for divergence to occur between the %R and the market.
As with all overbought/oversold indicators, it is often best to wait for the market’s price to change direction before placing your trade. For example, if Williams %R is showing an overbought condition (10% or lower), it’s wise to wait until the price turns down before selling that market.
It is not unusual for an overbought/oversold indicator to remain in an overbought/oversold condition for a long time period as the market’s price continues to climb/fall. Selling or buying simply because the market appears overbought or oversold may take you out of a trade long before the trend actually changes.
Commitments of Traders
- Commercial Positions: the difference between the Commercial Positions-Long (All) and the Commercial Positions-Short (All).
- NonCommercial Positions: the difference between the NonCommercial Positions-Long (All) and the NonCommercial Positions-Short (All).
- NonReportable Positions: the difference between the NonReportable Positions-Long (All) and the NonReportable Positions-Short (All).
Positive values represent Net Long positions while negative values represent Net Short positions.
CRB Yearbook Articles:
Commodity Futures Trading Commission (CFTC)
Historical Open Interest
The dashed line running parallel with the solid open interest line in PriceCharts is a six-year average of the total open interest.
CRB Yearbook Articles:
Williams Accumulation/Distribution Index (AD)
The Williams Accumulation/Distribution Index (AD) was developed by Larry Williams. It attempts to measure market pressures, specifically looking for market divergence, and serves to measure market strength and sentiment. You should watch for instances of substantial divergence between the AD and the underlying price direction as a key to future price direction.
If a market continues to move into new high ground, for instance, the AD should follow suit. When the market makes several new highs but the AD fails to make new highs, it’s a warning that the market may be about to reverse direction. Conversely, if the AD fails to make lower lows while market prices drift lower, it’s a signal that the market may be about to move higher. In either case, divergence implies a reversal in the dominant trend may be near.
Once you spot divergence, initiate a market position when a clear break occurs in the trendline of the AD. This minimizes the possibility of taking a position before the actual trend reverses.
The AD is computed several different ways. Some computations normalized the index, while others added extra smoothing factors through the use of moving averages. Commodity Price Charts uses the following computations to create and chart the AD index.
As a starting point, Commodity Price Charts sets the initial value of the AD index to zero. From there, we perform the following comparisons, which are logically and mutually exclusive. Only one of the three can be valid to correctly measure the market’s accumulation or distribution.
The first comparison checks for accumulation, i.e., is current close higher than previous close? If the market is accumulating, then compute the difference between current close and low. Next, add that arithmetic difference to the Accumulation/Distribution Index. The procedure is:
If Closet > Closet-1,
then ADt = ADt-1 + (Close t – Lowt)
The second comparison checks for no change in price. If correct, the AD index does not change. It states:
If Closet = Closet-1, then ADt = ADt-1
The last comparison checks for a down market. It checks for current close below previous close. If that is correct, the market is distributing. First compute the difference between current high and close. Then subtract that difference from the AD index. This measures market distribution. The final computation is:
If Closet < Closet-1,
then ADt = ADt-1 - (Hight - Closet)
ADt = the accumulation/distribution index for the current period
ADt-1 = the accumulation/distribution index for the previous period
Closet = the closing price for the current interval
Closet-1 = the closing price for the previous interval
Hight = the true high price for the current interval
Hight-1 = the true low price for the current interval
NOTE: The “true high” and “true low” are used in these formulas. The true high is the higher value of the current high or the previous close. The true low is the lower value of the current low or the previous close.
For detailed ADX information and explanation, refer to: New Concepts in Technical Trading Systems by J. Welles Wilder Jr., available from Trader's Library.
Tips on Technicals: The Directional Movement System