One strategy I have heard people discuss from time to time is using the 200-day moving average as a timing indicator. Stocks are purchased when a broad market benchmark is above its 200-day moving average, and stocks are sold when the market benchmark falls below its 200-day moving average. Though there are variations in the type of the moving average used, the basic premise is the same: Own stocks when the market is above the indicator and sell stocks when the market is below it.
In his new fifth edition of “Stocks for the Long Run” (McGraw-Hill, 2014), Jeremy Siegel looked at whether this strategy is beneficial. He ran the numbers from 1886 through 2012 using the Dow Jones industrial average. He applied a 1% band, meaning the Dow had to be at least 1% above its 200-day moving average to trigger a buy signal or at least 1% below its 200-day moving average to trigger a sell signal. The band is important because it reduced the number of transactions. Without it, an investor would be frequently jumping in and out, driving up transaction costs in the process. Siegel also assumed end-of-day prices were used.
Following the 200-day moving average timing strategy would have kept an investor out of the worst market downturns. Specifically, the investor would have avoided the large losses endured during both Black Tuesday (October 29, 1929) and Black Monday (October 19, 1987). The strategy would have also helped the investor avoid the 2007-2009 bear market.
Commenting on the results, Siegel observed, “The timing strategist participates in most bull markets and avoids bear markets, but the losses suffered when the market fluctuates with little trend are significant.” He added, “The timing strategy involves a large number of small losses that come from moving in and out of the market.”
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