A definitive down-day followed the post-FOMC announcement session today. As we often see, and as I warned in yesterday evening’s letter, the reaction we get is very often reversed, and that will signal the true trend. In fact, on several occasions the FOMC announcement ended up marking a short-term top. We had a break of key short-term support today, and the mid-day rally was not able to get us back through those levels.

The day started out with a big gap down and then they snapped back in corrective fashion, forming bear flags in the morning. They had a very sharp breakdown from those bear flags and a sharp sell-off that took out support. Two sharp rally attempts took them back up to resistance but they failed to break out, and then they rolled over in the last hour, closing at the lows for the day going away.

The Dow was down 148 points today, the S&P 500 down 21-plus, and the Nasdaq 100 down nearly 30 Ã,½. The Philadelphia Semiconductor Index (SOXX) was down about 10 Ã,¾.

The technicals certainly confirmed the very negative session, with advance-declines negative by 26 to 7 on New York and 24 to 6 1/2 on Nasdaq. Up/down volume was even worse, with about an 8 to 1 negative ratio on New York on total volume of more than 1.5 billion. Nasdaq traded more than 2.2 billion, with a 19 to 3 negative ratio.

TheTechTrader.com board was fairly narrowly mixed, but there were some outstanding gainers and losers. On the plus side, former portfolio position Force Protection (FRPT) soared 3.42 on 6 1/3 million shares, closing at 26.67.

Other gainers of note, Chindex (CHDX) gained 92 cents and portfolio position Ascent Solar (ASTI) gained 48 cents. Also firm in the solar energy sector, JA Solar (JASO) was up 36 cents.

On the downside, losers included DXP Enterprises (DXPE) down 2.19, Jones Soda (JSDA) 1.35, and NVE Corp. (NVEC) 1.27. Energy Conversion Devices (ENER) dropped 1.91 in a mixed solar energy sector.

Stepping back and reviewing the hourly chart patterns, a key break occurred today. Short-term support was taken out as well as the sharply rising trendlines of the last six weeks. So a key negative day today, and we’ll have to see if resistance near today’s rally highs, specifically at 1500 on the S&P and 1887-88 on the NDX, can provide a lid on the action.

Short-term support is below the current levels at around 1858-60 on the NDX and 1475-78 on the S&P. If tomorrow is anything like today, we could have another sharp down-session that tests those levels, but we haven’t seen many decent downside follow through sessions & that remains to be seen

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.