There is nearly £12bn invested in unit trusts that carry a performance fee in the UK, and £10bn in investment trusts that levy this extra charge.
Investment trusts on the whole carry smaller annual management charges than unit trusts – most unit trusts charge a standard 1.5pc annual fee, but the annual fees on investment trusts are closer to 0.6pc.
Performance fees can vary but the average unit trust with a performance fee charges 17pc, and the average investment trust charges 16.6pc. This is payable on top of standard annual charges.
This charge is a percentage of outperformance - typically compared to a benchmark, so a Chinese equities manager would take 17% of the amount by which he or she has outperformed the MSCI China index for example.
One of the biggest concerns with performance fees is their unpredictability. With a flat annual management charge (AMC) you know exactly how much the fund manager will slice off the top of your investment each year - with performance fees that top slice is variable.
Performance fees are complex - they cannot easily be compared like annual management charges.
The formula may be disclosed up front on an asset manager's website, but they are difficult to understand and almost impossible to calculate.
This is because they do not all follow the same formula. Some include caps, some do not. Some base calculations on a comparative benchmark index, some on the average performance of a fund's peer group.