Studies after studies in stock price behaviour have confirmed the existence of Post Earnings Announcement Drift (PEADS).
When a company announces earnings and they are surprisingly good or bad, the stock price continues to drift in the direction of the surprise for weeks or months. In simple language a stock with "significant" earnings surprise is like to go up for weeks or months.
The earnings season is now starting. Keep an eye on stocks that beat earnings by a mile. If pre earnings they were not rallying and consolidating for long period, the earnings can often start a big rally.
The information for finding big earnings surprise is freely available on most sites. Zacks has lot of free earnings information and charts that show earnings surprise history.
The earnings surprise information is also available on Zacks under earnings tab.
Earnings are released after market close or before market open and if you focus on the surprises you can find 3 to 5 good trades in e very earnings season.