Philip Hardy, Polar Capital

The best advice I was given when just starting out managing a hedge fund was from Tim Tachi, the founder of London-based hedge fund, TT International.

His advice was simple, practical and easy to implement, as often the best advice is.

I was told that if I had a position in my portfolio that was a constant source of concern and angst, then I should close the position so as to focus on the bulk of the portfolio.

This has served me well on a number of occasions, not least in times of market turmoil.