Most people like to average down. Is this a good strategy? It all depends on who you are financially and your personal traits. If you are a value investor, that is, an investor who buys sound solid companies at undervalued prices for the long term, you should certainly average down. Buy low and sell high is your way.
A trend can reverse direction at any time. As soon as you buy, the price drops. Your positive expectancy vanished. In this case, you must quickly sell to keep your losses small. Don’t compound your error by averaging down. If you are right, you can average up.