Investment banks might be hiring traders again, but they're still heading to the buy-side. : A $5bn hedge fund that focuses on the derivatives market has quietly been tapping the trading floors of large investment banks for its London operation. During the past two months, Capstone Investment Advisors, which has around 110 staff globally, has hired former UBS, Deutsche Bank and J.P. Morgan traders for its London office in Mayfair. Cherie Xiu Zhou, a vice president trading US dollar exotics within Deutsche Bank’s rates and credit team, has just joined Capstone as a trader.