Investment banks feeling the pinch from increased regulation since the financial crisis could reap an earnings reward from a boost in trading activity under the European Central Bank’s (ECB) trillion-euro quantitative easing (QE) program. The flood of money into markets from the ECB’s bond-buying has brought an increase in the volatility that traders crave as investors stake bets on the impact the scheme will have on inflation and long-term interest rates. “QE is likely to underpin a sustained period of strength in euro capital markets,” Citigroup said in a research note on Friday.