Greg Coffey, co-chief investment officer of Moore Capital Management LLC’s European business, is leaving the hedge-fund industry after a 20-year trading career, according to a letter sent to investors…Assets in Coffey’s macro fund have slumped to about $100 million from as much as $1.6 billion in 2010. The fund had fallen about 10 percent this year through August before rebounding almost 9 percent last month, according to people with knowledge of the matter, who asked not to be named because the information is private. The fund lost 5 percent last year. Coffey realized that after he had recovered most of this year’s losses in one week in September, he wasn’t as excited about his gains as he might have been in the past, two people who know him said. Coffey then decided it was time to end his 20-year career trading, the people said.