DAR ES SALAAM, Oct. 6 -- WHAT if the share price of a company you own falls by 15 per cent tomorrow? Will you panic and sell, or will you see an opportunity to own more of the same investment at a lower price? And what if the price rises by 20 per cent? Will you recognise that your existing investment has just become more valuable?

This is where the difference between a reactive investor and a serious investor becomes clear: The serious investor understands that both rising and falling prices can contribute to long-term portfolio growth.

The stock market does not move in a straight line. Prices rise and fall in response to company performance, investor sentiment, economic conditions, interest rates, global developments and many other fa...