LONDON, July 9 : Some hedge fund managers have in recent weeks posted their worst trading results in almost a year, as many got caught in crowded trades amid highly volatile markets, according to Goldman Sachs.Goldman said in a note dated Wednesday that systematic managers — sometimes called quant funds — that use algorithms to trade market trends, have given back a quarter of their year-to-date returns. Returns for this group of traders are now up 10.8 per cent for the year, down from a return of 14.4 per cent on June 22. Losses came from bets against some of the biggest and most crowded parts of the market right now — U.S. equities, Asian developed-market stocks and, to a lesser extent, Europe, the note said.Huge volatility in shares of chipmakers had made for a tricky trading environmen