The stop-loss dilemma

This technique enables an assessment of the potential cost if things go wrong. If the investors buy a stock at $100 with a stop-loss price of $75, they know in advance that their maximum loss is $25. There are also other variants which aim to limit the potential reversals of profitable positions. With a trailing stop-loss, the stop-loss price rises in line with the market price. So if the market rallies by $10 to $110, the stop-loss price might also rise by $10 to $85.

The benefits of a stop-loss

It forces an investor to be disciplined. When a position goes wrong, it can cause stress and cloud people's judgement. Anticipating this, and deciding on a stop-loss level in a calm and relaxed manner beforehand, can ensure that an investor will remain objective.

A stop-loss also allows a specific amount of capital to be allocated to each idea. So an investor might be prepared to lose say, $10,000 on a hunch, and say, $25,000 on a firm conviction.

The argument against stop-loss

It doesn't seem very scientific.

Is this necessary if the other risk management ideas are followed?

The choice to cut a losing position is a dilemma.

On the one hand, the positives for managing risk and preserving capital are clear.

On the other hand, if you are confident an investment is a good idea but the price moves against you, perhaps you should be buying more, or at least holding, rather than cutting.

How you may overcome this dilemma?

One discipline which you should use is to value your position regularly using the current market price. A losing position clearly means that something unexpected has happened.

When you invest, have a stop-loss in your mind. If your investment hits the stop-loss level, make a judgement on whether to cut, based on your confidence at the time about the position.

If the loss is threatening to be destructive to your finances, it is absolutely vital to cut. To be at this point, the price must have moved a really long way against you, if you have not bet too much on the idea in the first place.

You must also cut if you are confused about what is going on, or if the fundamentals are moving against you. In these situations, you see the prices go further than expected.

The decision not to cut

There are times not to cut a position, even if it reaches your stop-loss level. These are when two conditions are satisfied:

1. you have the capital in case of further losses;
2. you understand the reasons for the adverse price move, but remain confident that there will be a recovery.

Here it may make sense to hold the position and even to consider buying more. (It is sensible to see the market starting to recover before adding to a position.)

The decision to keep a losing position must not be based on emotion or on any sense of living in hope. You must admit to yourself that things have not gone the way you expected, and that since you have been wrong up to this point, you may well be wrong again. There is an old saying along the lines of 'the market can remain irrational much longer than you can remain solvent'.

Summary

Stopping out is the hardest transaction. No one likes to give up hope. But it is essential in some circumstances. Beginner investors should be especially cautious about mounting losses.

Sometimes you cut a position and then the market recovers. Don't be put off stop-losses by those experiences. The horrible feeling of cutting a position only to watch the price turn and recover is one of the worst for an investor. You are talking about probability and random events, and over time all sorts of good and bad things will happen. You have to look at the long term. Normally after cutting a bad position there is a strangely cleansing feeling - some people say it's a bit like getting out of a bad relationship!

Stop-loss maybe unnecessary for some or many investors if the other risk management ideas are followed.