Markets have become more oversold with every correction since the lows of mid-April. For buyers of weakness, a continuation of the selling we've seen over the past few days could provide even better opportunities to buy strong stocks on sale.

Thinking about stocks and stock markets this way can be a change of pace for many short term stock traders who have been conditioned to think "rising markets = good, falling markets = bad." Like everything else in life, context is key.

If you own stocks, then a rising market is good. But if you are looking to buy stocks, do you want stocks to be moving higher or lower?

For many short term stock traders, the answer is higher. Many short term stock traders have been led to believe that the only way to buy stocks is to buy them as they "breakout" - essentially, as they become more expensive.

This is a popular approach. But it may or may not be the best one. We believe that stocks, like most everything else we buy, are best purchased at as low a price as possible. If the asset - in this case the stock - is valuable, then buying it when its price is low and temporarily depressed makes it that much easier to sell as the markets notices the mispricing and the value of the asset appreciates.

This is the core of our approach to swing trading. And when combined with our Short Term PowerRatings, this strategy of buying stocks when they are low and selling them when they are high is one we have found to be very successful in our historical testing, as well as in the real-life trading we do as part of our TradingMarkets Battle Plan for Stocks (to learn more about the Battle Plan for Stocks, click here).

How do our Short Term PowerRatings work for traders? At their most basic, our Short Term PowerRatings help traders screen for those stocks that are most likely to outperform the average stock over the short term trader's "sweet spot" of five to eight days. Stocks with the highest Short Term PowerRatings, stocks with Short Term PowerRatings of 10, actually outperformed the average stock by a margin of nearly 17 to 1 in five day's time based on our historic testing. At the other end of the spectrum, stocks with Short Term PowerRatings of 1, our lowest rating, tended to underperform the average stock by a margin of nearly 5 to 1 after five days.

By looking to buy high Short Term PowerRatings stocks when their prices are low, traders can gain a powerful edge that will ensure that they are both buying strong stocks as well as buying stocks that have become cheaper and more attractive.

All five stocks in today's report have Short Term PowerRatings of 8 or higher. Our research into short term stock price behavior between 1995 and 2007 indicates that stocks with Short Term PowerRatings of 8 outperformed the average stock by a margin of more than 8-1 within five days.

Stocks with Short Term PowerRatings of 9 performed even better, beating the average stock over five days by a margin of more than 13 to 1.

I have also included the 2-period Relative Strength Index values for each stock. We consider a stock oversold when its 2-period RSI is below 10, with 2-period RSIs of less than 2 marking extremely oversold conditions that can lead to powerful rallies in response.

WSI Industries Inc. (WSCI | Quote | Chart | News | PowerRating) Short Term PowerRating 9. RSI(2): 2.94

First Advantage Corporation (FADV | Quote | Chart | News | PowerRating) Short Term PowerRating 9. RSI(2): 2.70

Ion Geophysical Corporation (IO | Quote | Chart | News | PowerRating) Short Term PowerRating 9. RSI(2): 2.45

Murphy Oil Company (MUR | Quote | Chart | News | PowerRating) Short Term PowerRating 8. RSI(2): 4.03

Aaron Rents Inc. (RNT | Quote | Chart | News | PowerRating) Short Term PowerRatings 8. RSI(2): 9.41

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 for TradingMarkets.com.