The markets had a strong slide after a morning rally that sent them to the lows of the day near the close, definitely a bad day for the bulls.

The day started out with a move lower. They quickly reversed that and rallied sharply, with the S&P 500 getting back up to yesterday's highs and up to formidable overhead resistance near 780. When that occurred and the Nasdaq 100 was still about 10 points off its high and diverging negatively, the indices turned around and came down quickly. They did bounce off the morning lows, but failed to follow through and then rolled over. That triggered a sharp afternoon slide that ended up near the lows for the day at the end of the session.

Net on the day the Dow was down nearly 89 to 7182, the S&P 500 was down 12.07 to 752.83, and the Nasdaq 100, which was the weak sister today, dropped 33.73 to 1127. The Philadelphia Semiconductor Index (SOXX) dropped 3.60, closing at 201.47.

Advance-declines slid into a negative plurality by the end of the day, with about 280 net issues lower on New York and more than 650 lower on Nasdaq. Up/down volume was 4 to 3 negative on New York on total volume of just under 1 1/2 billion. Nasdaq traded 2.3 billion and had a 3 1/2 to 1 negative volume ratio.

As a result of the afternoon slide, most of the stocks on TheTechTrader.com board ended a bit lower.

Obviously most of the ultrashorts had a good day. Leading the way was the SRS ultrashort real estate ETF, up 6.38 to 78.38, 11 points off its earlier low, so a complete reversal there. The Direxion Large Cap Bear 3X Shares (BGZ) at 86.08 was up 3.86, closing 9 points off its low.

Point-plus gainers included Potash (POT), up 3.18 to 83.84, and Mosaic (MOS) up 54 cents to 39.66, but closing 2 points off its high. Agrium (AGU) got hammered for 1.68 as a follow-up to yesterday's merger with CF.

The U.S. Oil Fund ETF (USO) had a good session, up 1.27 to 27.27 on 47 million shares, as oil advanced for the third straight day, closing over $45 a barrel.

Most other stocks on my board were fractionally changed either way. Wells Fargo (WFC) was up 96 cents to 14.40, reaching over 15 at one point, and JP Morgan (JPM) gained 1.32 to 23.05.

Stepping back and reviewing the hourly chart patterns, yesterday's rally failed to take out key overhead resistance, and they paid the price today, as the indices came down hard, with the NDX retesting its low of 1127 from earlier in the week. The SPX is a bit above its low, but the lack of follow-through to yesterday's rally and promising late move is technically negative and does not augur well for future price progress. But we'll have to see if key support is able to hold.

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.