NEW YORK (CNNMoney) -

A fund manager’s divorce can tank a hedge fund’s performance. The only thing that’s worse for it is a wedding.

A fund’s alpha — the measure of how much it beats the market — falls by an annualized 8.5% around the time of a manager’s marriage, according to a study released this month by University of Florida economists. The alpha dips 7.4% during a divorce.

It’s surprising that marriage actually does more damage to a fund manager’s performance, according Dr. Sugata Ray, one of the paper’s authors.

Divorce has always been a red flag for savvy investors. Hedge fund manager Paul Tudor Jones II, said he withdraws his money from a fund when a manager’s marriage breaks up.

You can automatically subtract 10% to 20% from any manager when he is going through a divorce, he told a conference in 2013.

(Jones also famously noted at that same conference that women who have children can’t be great traders, so perhaps we’ll take his opinion with a grain of salt.)

Marriage is most detrimental to older managers who use a strategy of trading frequently. Performance among those above the median age of 49 years old fell 14.3% around their weddings, while marriages barely affected young managers.

Younger fund managers tend to have more performance problems around a divorce. The annualized alpha of younger fund managers fell by 15.7% when they got divorced, while older managers only lost 4.1%.

One hedge fund titan who hasn’t been affected (yet) by marital strife is Citadel’s manager Ken Griffin, who is in the middle of one of the most public and nasty divorces in recent memory. Despite that, his company’s three big funds have continued to outperform the market.

It depends on how much of the secret sauce is actually coming from him, said Dr. Ray.

Another big factor is whether a fund manager has partners to help steer the ship during a crisis.

Managers that work alone get clobbered when they go through marriages and divorces, said Ray. They start to fall prey to behavioral biases, like selling their gains and holding on to their losses longer than they should.

The findings were based on data collected from 1994 to 2012, tracking 786 managers who went through 857 marriages and 251 divorces.