The stock market indices started the week out on a positive note, although a last half-hour sell off took back a chunk of the profits.

The day started out with a gap up and strong early morning rally that took the Nasdaq 100 to new highs at 2127 and the S&P 500 to 1196. They then sold off, backed and filled, consolidated, and tried an afternoon rally, which got up to the morning highs but couldn’t quite break out late and run. When that occurred, they rolled over hard in the last half hour to pare back the gains.

Net on the day, the Dow was still up 31.49 at 11,164.05. The S&P 500 managed to eek out a 2.54 gain at 1185.62, 11 points off its high. Nasdaq 100 closed 14 points off its high, up 9.34 at 2113.55.

Advance-declines were 3 to 2 positive on the New York Stock Exchange and 8 to 5 positive on Nasdaq. Up/down volume was 2 to 1 positive on New York on total volume of just under 1 billion. Nasdaq traded nearly 1.75 billion and had about 11 1/2 to 6 positive ratio on advancing volume over declining volume.

TheTechTrader.com board was mostly higher. Leading the way today was Sohu.com Inc. (SOHU), up 9.17 to 74.93. Other point-plus gainers of note included Motricity, Inc. (MOTR) up 2.42 at 19.90, Radware Ltd. (RDWR) 2.52 at 35.93, Trina Solar Ltd. (TSL) 1.23 at 27.47, and JinkoSolar Holding Co., Ltd. (JKS), up 1.03 to 27.12, both in the strong solar group.

In addition, Sourcefire (FIRE) jumped 1.38 to 31.48, Cree Inc. (CREE) 1.20 to 51.40, and Acme Packet, Inc. (APKT) 1.01 to 39.98. Apple Inc. (AAPL) eked out 1.37 to 308.84.

On the downside fractional losers included Brigham Exploration Co. (BEXP), which backed off 59 cents to 20.35. Goldman Sachs (GS) lost 37 cents to 157.39, and did not participate today. Isilon Systems, Inc. (ISLN) was down 79 cents to 28.46, and VirnetX Holding Corp (VHC) dropped 65 cents to 16.96.

Stepping back and reviewing the hourly chart patterns, the indices were up sharply at the opening, including an opening gap, which brought them to new 2010 highs. They then backed and filled most of the session, tried to rally late but then rolled over to close near the session lows at key session support.

We’ll see if there’s any downside follow-through tomorrow or not. In any case, another positive start to the week.

Harry Boxer is a technical consultant to many Wall Street hedge funds and large institutional traders, and author of TheTechTrader.com.