Stock market futures are negative this morning, as investors consider unexpectedly strong data on the labor market. Nonfarm payrolls increased by 263,000 in November, versus a revised gain of 284,000 in the prior month. The major market indexes may be hard pressed to post improvement for all of this week. Over the first two and one-half days of trading, share prices generally moved lower. Then, on Wednesday afternoon stocks surged higher following remarks from Fed chair Jerome Powell. Today’s data, however, has put a damper on momentum.