An FX strategist at Brevan Howard, who went into hedge funds after two years as a grammar school physics teacher, has become the latest senior exit. Teaching is often viewed as a vocation to escape financial services careers, but Oliver Brennan worked at the selective Dr Challoner’s Grammar School in Buckinghamshire for two years before joining Brevan Howard in 2007. Brennan spent three years at Brevan Howard before leaving for State Street Global Investors in 2011. He spent less than a year there before moving to Tudor Investment Corporation in February 2012, but returned to Brevan Howard by August that...