Bentley says it is important to consider the bigger picture and that companies that do well will perform irrespective of whatever the economic backdrop is like.
Many small companies carve out a niche that enables them to do well, he adds, pointing to Apple as classic example of this when it started up.
He also identifies a variety of indices where small companies can be found, including the Alternative Investment Market, and highlights how it is important to have a sizeable number of companies in the portfolio to reduce the level of risk.
As to the question of what happens at the point when a company is no longer small anymore, Bentley says there is no hard and fast rule on when to sell.