模仿文本：The BBC has learnt that the banks were aware of problems in foreign currency markets here in London, four years before the Financial Conduct Authority began its investigation into exchange rate fixing. Analysts noticed sharp movements in exchange rates each day at 4 pm and warned their clients it could hit the investments. I've been getting more details from our chief economic correspondent Hugh Pym.

BBC获悉，早在金融监管局开始调查汇率调整问题的四年前，银行就已经知晓伦敦外汇市场存在的问题了。（银行）分析人士发现，汇率每天下午四点都会出现巨大波动，并且告知了其客户这种情况可能会影响他们的投资。更多细节，我采访到了我们的首席财经记者Hugh Pym。