(Bloomberg) Hedge funds attracted a net $44 billion in assets globally last year, the smallest amount since 2012, according to data compiled by Hedge Fund Research Inc. That reflects a volatile year, when unanticipated economic events rattled markets and led to declines and losses for many funds. Others were hurt by crowded and sometimes concentrated trades and poorly timed bets on energy as oil prices continued to fall.This special report on 2015 Hedge Fund Rankings looks at two groups — the top 50 best performers with $1 billion or more in assets and the top 25 best-performing hedge funds with $250 million to $1 billion in assets.