This proprietary screen is produced by Investor's Business Daily (IBD) and reveals stocks currently experiencing unusually heavy buying and selling. This idea-generating list is continuously updated throughout the market session as new stocks experience unusual trading. Unusual trading volume can signal heavy activity by institutional investors (pension and mutual funds, banks, insurance companies, corporations and government organizations).

A stock moving up in price on higher than normal volume indicates strong buying conviction that could carry the stock even higher. A stock headed lower on big volume increases could signal strong selling pressure and an emerging downward trend.

To determine unusual activity, Investor's Business Daily measures every stock's current trading volume. Each stock's current volume is then compared to its normal trading by this time in the market session, based on the last 50 trading days. The percentage change is then computed, alerting you to unusual activity while it's happening.

Stocks moving up on unusually high volume may warrant further research. IBD Stock Checkup and IBD Charts can help you research these prospects further.

The qualification criteria for listing:

• Stocks must trade on the Nasdaq or New York Stock Exchange.
• Stock price must be at least $20.00 ($16.00 for Nasdaq).
• Stocks must have a price change of 1/2 point or more.
• 50-day Average Volume must be a minimum of 60,000 shares.
• For stocks up in price only, the Earnings Per Share (EPS) and Relative Price Strength (RS)
• Ratings must each be a minimum of 70, Accumulation/Distribution Rating must be D+ or better and next year's earnings estimate must be 15% or higher from the previous year's earnings. (Stocks without earnings estimates are included.)