The stock market indices ended narrowly mixed today, but after a very strong morning rally they rolled over hard in the afternoon and gave back all the gains and then some, or nearly so on most of the indices.

The day started out with a big gap up. They backed and filled in the morning and formed bull consolidations and then broke out late in the morning to reach the session highs before lunch hour. The Nasdaq 100 reached 1976 and change, and the S&P 500 reached over 1180 to just under 1181, but then they rolled over hard and closed at the lows for the day going away in what looked like an impressive reversal day. The indices closed right on their rising moving average on the hourly charts, so there is some support in the zone. We’ll see if there’s a downside follow-through tomorrow. If there is, they may attempt to break the back of the trend.

Net on the day, the Dow was up 5.06 at 10,841.21, down from a session high of 10,955, so about an 114-point reversal from up 119 to only up 5. The Nasdaq 100 was down 2.69 to 1949.15, 30 points off its high and a complete reversal of a 28-point gain into a loss. The S&P 500 closed at 1165.73, down 1.99, which was 15 points off its high.

The technicals were mixed, but advance-declines were about 3 to 2 negative on the New York Stock Exchange and about 8 to 5 negative on Nasdaq. Up/down volume was about 2 to 1 negative on New York and about 2 1/2 to 1 negative on Nasdaq.

TheTechTrader.com board was mostly negative, but there were some gainers today. Point-plus gainers included Salix Pharmaceuticals (SLXP) on positive news reaching as high as 38 but reversing and closing at 35.29, still up 1.77 but way off its high.

Other point-plus gainers included American International Group (AIG), closing at 34.51, about a point off its high but still up 1.34 on heavy volume of 294 million shares.

Other large fractional gainers of note included kechers USA (SKX) at 36.23 up 80 cents, again down about a point from its high. Acme Packet, Inc. (APKT) closed at 19,97, up 95 cents and reaching up to 20.25 at one point, a new multi-year high. China Automotive (CAAS) at 22.69 was up 50 cents, again about 1.80 off its high.

There were big reversals today, but some stocks still closed in the plus column and they included Somaxon Pharmaceuticals (SOMX) at 9.51 up 26 cents, Pixelworks Inc. (PXLW) at 5.60 up 27 cents, and PLX Technology (PLXT) at 5.51 up 7 cents. Those three stocks are portfolio positions.

Integrated Silicon Solutions (ISSI) closed up at 9.69 up 44 cents, Callon Petroleum Co. (CPE) at 5.38 up 21 cents, and China Recycling Energy Corp (CREG) at 5.90 up 25 cents.

On the downside the loss leaders included Dendreon (DNDN) off 1.04 at 36.61, down from a 38.10 high earlier today.

Other fractional losers included Brigham Explorations (BEXP) at 15.59 down 71 cents, and Houston American Energy Corp. (HUSA) at 17.24 down 53 cents in a weak junior oil sector. JAZZ Pharmaceuticals (JAZZ) lost 50 cents to 12.33, Las Vegas Sands Corp. (LVS) 97 cents to 20.93, and McMoRan (MMR) 57 cents to 14.77, also in the junior oil sector.

Radware (RDWR) at 21.04 fell 57 cents, and RINO International (RINO) at 23.73 was down 37 cents, along with TiVo Inc. (TIVO) down 35 cents to 16.24, and TASER International Inc. (TASR) off 32 cents to 6.31.

Stepping back and reviewing the hourly chart patterns, the indices gapped up at the get-go, consolidated in early morning, and then reached their session and new 2010 highs before noon before rolling over the rest of the session and closing at the session lows. So, potentially a significant reversal day.

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