The stock market indices had a very strong last-hour rally to close in the plus column after having given up all their gains and moving into the red.

After a strong opening, the indices gapped up, ran hard, reaching just under 1980 on the Nasdaq 100 and right at key overhead resistance just over 1181 on the S&P 500. Then they backed off in a strong sell-off that we saw the NDX drop just under 1980 to under 1945, a 35-point drop. The S&P 500 dropped from 1181 to 1171 before the snapback.

Net on the day, the Dow closed up 70.44 at 10,927.07, the S&P 500 up 8.67 at 1178.10, and Nasdaq 100 up 1.22 at 1959.56, still 20 points off its high. The Philadelphia Semiconductor Index (SOXX) was up 0.36 after being up nearly 9 earlier in the day.

Advance-declines were about 3 to 1 positive on New York Stock Exchange and 15 to 11 positive on Nasdaq. Up/down volume was nearly 7 to 1 positive on New York, but 11 to 10 negative on Nasdaq.

TheTechTrader.com board was mixed, but there were some point-plus gainers today. Leading the way on the upside was Green Plains Renewable Energy (GPRE) at 15.41, up 1.14. Among the junior oils that had a very strong session was Gulfport Energy (GPOR) at 13.42 up 2.18, Houston American Energy Corp (HUSA) at 19.62 up 1.47, and Brigham Exploration (BEXP) at 17.12 up 1.17.

Other gainers of note, Salix Pharmaceuticals (SLXP) at 38.60 was up 1.35. Ardea Biosciences (RDEA), which gapped up early on big news, closed up 2.24 for the day at 20.50 with a high today of nearly 24. Air Transport Services Group (ATSG) had a wonderful follow-through to yesterday's strong session, closing at 4.17, up 82 cents.

Large fractional gainers included Incyte Corp (INCY) at 14.30 up 37 cents. McMoRan (MMR), also in the oil sector, closed at 15.30, up 67 cents. Pharmacyclics (PCYC) gained 39 cents to 6.63, Sketchers (SKX) 70 cents to 37.02, Dendreon (DNDN) 55 cents at 37.02, and Amylin Pharmaceuticals (AMLN) 60 cents to 23.09.

On the downside Chinese stocks were soft. China Agritech (CAGC) lost 1.87 to 22.99 and China Automotive (CAAS) 68 cents to 22.42, but RINO International (RINO) had the biggest loss in that sector today, down 2.55 to 21.18 after releasing earnings.

Stepping back and reviewing the hourly chart patterns, the indices were up sharply at the opening, rallied to new 2010 highs on the Nasdaq 100 just under 1980, and fractionally on the S&P 500 as well just over 1181, but reversed sharply by mid-morning and then dropped sharply into mid-afternoon. With an hour to go they rallied sharply, took back a very large portion of the pullback and still closed positive today as noted earlier.

So, despite downside pressure today the market managed to right the ship and close very impressively with solid technicals as well.

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