The market hiccupped a bit Thursday and the S&P 500 gave up its 50-day moving average in higher volume — a stern reminder that market conditions remain unsettled even with major averages holding near highs. It’s not an environment in which to be overly aggressive with news buys. Some exposure is OK, but it’s generally a good idea to take a modest gain when when you have it, and cut losses quickly if a new buy doesn’t pan out.