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When following a buy and hold investment strategy, on what conditions should one sell?
You talk about an individual not being advised to sell (or purchase) in response to trends in the market in such a buy and hold strategy. But think of this for a moment: You buy stock ABC for $10 when both the market as a whole and stock ABC are near the bottom of a bear market as say part of a value buying strategy. You've now held stock ABC for a number of years and it is performing well hitting $50. There is all good news about stock ABC, profit increases year after year in double digits. Would you consider selling this stock just because it has increased 400%. It could start falling in a general market crash or it could keep going up to $100 or more. Maybe a better strategy to sell ABC would be to place a trailing stop of say 20% on the highest price reached by the stock. So if ABC falls, say in a general market correction, by less than 20% off its high and then rebounds and goes higher - you keep it. If ABC however falls by more than 20% off its high you automatically sell it with your stop loss order. You may give 20% back to the market if the market or the stock crashes, but if the stock continues going up you benefit from more upside in the price. Take AAPL as an example, if you bought AAPL in March 2009, after the GFC, for about $100, would you have sold it in December 2011 when it hit $400. If you did you would have left money on the table. If instead you placed a trailing stop loss on AAPL of 20% you would have been still in it when it hit its high of $702 in September 2012. You would have finally been stopped out in November 2012 for around the $560 mark, and made an extra $160 per share. And if your thinking, how about if I decided to sell AAPL at $700, well I don't think many would have picked $700 as the high in hindsight. The main benefit of using stop losses is that it takes your emotions out of your trading, especially your exits.