The Friday sell-off and continued weakness into this week means that many of the opportunities that have emerged in recent days remain available to short term stock traders.

Among those opportunities are three stocks DRD Gold (DROOY | Quote | Chart | News | PowerRating), Cyberonics (CYBX | Quote | Chart | News | PowerRating) and Columbus McKinnon (CMCO | Quote | Chart | News | PowerRating), all of which have Short Term PowerRatings of 9, all of which should be high on the lists that short term stock traders are maintaining as the markets continue to move lower.

Although buying weakness and selling strength makes sense in theory, the practical applications of this ages-old approach to trading can be daunting. Buying weakness and selling strength requires traders, for example, to see markets that are in correction mode as opportunities to buy strong stocks that are temporarily weak rather than a time to abandon stocks altogether.

What about short selling? We believe the time to sell stocks short is not when the markets are in correction mode, but as markets are moving higher. As I have written before, markets that are to be sold short are markets that are trading below the 200-day moving average and are actually moving higher, rather than lower. In the same way that we look to buy below the previous close when trading pullbacks, we look to sell above the previous close when trading bounces.

I have referred to this--when talking about the long side--as the pullback after the pullback. When buying stocks, we look first for an initial pullback. That is what alerts us to the trading opportunity. In terms of actually taking a position, however, we need still more weakness. Specifically, we are looking for intraday weakness to push the stock down a little bit more--typically anywhere from as little as 1% to as much as 8% below the previous close, depending on how aggressive we want to be. It is that extra bit of weakness that gets us into positions at the lowest possible levels.

This is a point worth emphasizing because it can dramatically affect your returns as a short term trader. We like to buy weakness and, under the correct conditions, the weaker the better. So it is our preference to buy at least 3-4% below the previous close--at least. This results in fewer trades, but the trades that do get triggered tend to be much more profitable than if we has merely used a 1% entry rule or, even more problematic, simply bought high Short Term PowerRatings stocks as soon as we saw that they had a high rating of 9 or 10.

Which brings us to the stocks in today's report. Again, all three stocks in today's report have Short Term PowerRatings of 9. According to our research, which looked at millions of simulated short term stock trades between 1995 and 2007, indicated that stocks with Short Term PowerRatings of 9 outperformed the average stock by a margin of more than 13 to 1 after five days.

In addition to the PowerRatings charts for each stock below, I have noted the 2-period Relative Strength Index values, as well. Note that all three stocks have exceptionally low 2-period RSIs of less than 6.

DRDGold RSI(2): 0.952

Cyberonics RSI(2): 4.29

Columbus McKinnon RSI(2): 5.72

Does your stock trading need a tune-up? Read our special, Free Report, "5 Secrets to Short Term Stock Trading Success" for a refresher course on not just why to buy low and sell high, but specifically how you can use intraday weakness in the market to do so. Click here to get your copy of "5 Secrets to Short Term Stock Trading Success" or call us today at 888-484-8220.

David Penn is Senior Editor at TradingMarkets.com.