The indices had a snapback session today, led by the Nasdaq 100. Despite a sharply lower opening, they immediately reversed and had a very strong rally on the Nasdaq 100, taking it from 2117 to 2160 inside of about 40 minutes. The S&P 500 did respond, but in a much more muted manner, as did the Dow.

Then they sold off and retested the lows on the blue chips, with the NDX doing about a 50% retracement. A secondary rally ensued, which lasted into early afternoon, falling just short of the morning highs on the Nasdaq 100 and testing multi-session declining tops line resistance. In the afternoon a slow orderly pullback retested support, and late in the session they snapped back again to close positive on the session.

At the close, the Dow was up nearly 45, the S&P 500 5.70, and the Nasdaq 100 nearly 26.40. The Philadelphia Semiconductor Index (SOXX) was up 4.81, around 1 percent.

The technicals were much better on Nasdaq than they were on New York, particularly on the up/down volume, where it was a better than 3 to 1 ratio, with about 2 billion traded. The NYSE traded about 1.4 billion and had about an 8 to 5 positive ratio. Advance-declines were ahead by about 300 issues on The NYSE and by about 575 issues on Nasdaq.

TheTechTrader.com board was very mixed today, with mostly gainers, as many issues came off the sharply lower early morning lows and closed higher. DryShips (DRYS) got down to 103 1/2 but closed at 119 1/2, a 16-point run, up 4 1/2 on the day. CYBS was up 1.68, DG FastChannel (DGIT) up 1.49, Home Inns & Hotels (HMIN) up 3.40, Sigma Designs (SIGM) 1.04, and Taser (TASR) 1.10, along with VMware (VMW) , up 4.64.

BPHX soared to new 9-year highs, closing at 19.62, up 2.29.

On the downside, the point-plus losers on our board were FuelTek (FTEK), on a downgrade, down 2.24, and TBSI in the shipping sector, down 4.04.

Stepping back and reviewing the hourly chart patterns, it was a fairly volatile, but somewhat contained session price-wise, and it appeared to be a technical snapback from the steep slide we experienced on Friday at options expiration. The Nasdaq 100 lead, but fell short of its 40-day moving average and price resistance around 2160 on at least 2-3 occasions on its hourly chart.

So we'll see if there's an upside follow-through, or whether they fail at resistance and roll over to retest the lows or take them out.

Harry Boxer is a technical consultant to many Wall Street hedge funds and large institutional traders, and author of TheTechTrader.com, a real-time diary of his day, swing and intermediate-term trades. For more of Harry Boxer, sign up for a free 15-day trial to his Real-Time Technical Trading Diary, or sign up for a free 30-day trial to his Top Charts of the Week service.