There was quite a bit of talk yesterday about traders shorting the ASX 200 on a break of the 200-day moving average at 5103. I ran analysis on how successful you'd be if you went short (assuming starting capital of $100,000) on a daily close below the 200-day moving average and again assuming you close the trade when the index closed back above the 200-day moving average and the results show it is not a profitable strategy at all. Effectively, since the GFC low (March 10 2009) you'd be down 16.2%, having placed twenty-six trades, with a 93% of these resulting in a loss. The average win would be $937, while the average loss would be $3170 and the position would be open for an average of 937 days. To summarise, use the 200-day as a guide to the longer-term trend, but a trigger for a trade. Forget it.