Money invested in equities - stocks and shares and equity markets – can fall as well as rise, so you take on this risk when you invest.  If your ISA or investment account provider falls into difficulties and goes bust for example, this is a different situation – and the money in your account is protected under the Financial Services Compensation Scheme (FSCS) up to £85,000 per person per investment group. But the FSCS does not provide compensation for losses due to poor investment returns.