Disparities in pension funds proved to be more alarming, with some high-risk options nearly tripling savers' money while others wiped out investments almost entirely over a five-year period. A common mistake could cost your ISA or pension pot up to £100,000 | GETTYStocks and shares ISAs typically fall into four main portfolio types, adventurous, balanced, cautious, and conservative, with risk levels decreasing in that order. The ISA limit is currently £20,000 each tax year | PACould you lose out on serious savings? For someone who had diligently built up £50,000 in ISA savings, the top-performing fund would have turned that sum into £162,490 over the same ten-year window. Among high-risk pension funds, the best performer delivered cumulative returns of 180.28 per cent over five years from 2020, while the worst lost a devastating 98.59 per cent of its value.