Thomson Reuters Highfields Capital Management, a $13 billion hedge fund, has raised concerns about quant funds and passive investing in a letter to clients seen by Business Insider. Quants use algorithms to make investment bets while passive funds track market indices. Both are challenging active managers, the human-backed stock pickers that have traditionally dominated Wall Street. Quants in particular could worsen the next financial crisis, according to Highfields, an active manager. A $13 billion hedge fund that flies under the radar is sounding the alarm on one of the biggest investment trends – quants and passive investing. Highfields Capital Management flagged concerns about computer-driven trading in its second-quarter letter to investors this week, a copy of which was reviewed by Business Insider. Boston-based Highfields uses a fundamental, value investing strategy, and though it is one of the biggest hedge funds, doesn't often get much attention. Quants could effectively worsen the next financial crisis, Highfields' founder Jonathon S.