I post this chart to illustrate how the crudest, simplest exit system is better than none at all. A 200 day moving is often used by conservative investors to keep them on the right side of major trends. The blue arrows mark entry and exit points as signaled by this indicator. You can see that while it is late to buy and late to sell, at least it protected some of the profits made over the previous 17 months. A 200 day moving average is a fairly blunt instrument, but in comparison with simply "buying and holding" it performs magnificently!
The Trailing Stop featured on the chart is derived from the Average True Range, but those of you without access to this indicator will find that a simple 13% trailing stop gives very much the same plot. A trailing stop is almost invariably quite late to trigger, but, again, infinitely better than no exit strategy at all.
I feel sorry for the poor sods that have been holding PGW all the way down this steep and on-going downtrend but that's what happens when you have no exit strategy and ignore market sentiment. There was plenty of warning and plenty of time to get out of PGW before the plunge.
http://h1.ripway.com/78963/PGW220.gif