The U.S markets are observing the Christmas holiday today, so that gives us a chance to take a closer look at the psyches of investors. To do that, we called on Peter Troob, a hedge fund man and co-founder of Troob Capital Management in White Plains, New York.

While the U.S markets did pretty well last week, some investors were sure to move their positions into the money markets, also known as cash, ahead of the long Christmas weekend…just in case. In preparing for any break from the markets, Troob says investors worry about surprises — a rumor or a headline (or even a Tweet) anywhere in the world can leave you on the wrong side of a trade.

Looking back on the year, Troob says there’s been a growing herd reaction to news. People get extra jumpy in these days of increasingly market volatility. If you step away from your desk to grab a sandwich, you may come back to find the market down a hundred or more points. That kind of instability has trained traders to always be watching for the next rumor.