How about this for an explanation for the weakness in stocks over the past few days: The computers are messing with us

How about this for an explanation for the weakness in stocks over the past few days: The computers are messing with us

I’ve read all the headlines explaining today’s drop in stocks, and yesterday’s and the day before. The chaos at OPEC and in oil prices. Fears that the economic recovery is slowing. Thoughts that inflation isn’t a worry and that instead we should fret about deflation. There is some truth to all these explanations. But I don’t see much of the way in news to support a major change in market trend and sentiment. And when I see a big, fast move like that of the last three days or so without much in the way of news to change investors’ view of the world, my thoughts turn to computers and program trades

The big role of computer program trading in the recent sell off in U.S. stocks is actually a positive, history says, for an early recovery

The big role of computer program trading in the recent sell off in U.S. stocks is actually a positive, history says, for an early recovery

Earlier than usual end of the year profit-taking. Sector rotation. Stretched valuations. All seem to have played a role in the retreat in momentum stock that has driven U.S. stocks lower in the last 10 days. And now we’re getting experts on program trading pointing at the role of computers in the slump and especially systematic trading programs that rely on weighting what the strategy calls “factors” to guide buys and sells.