Travelzoo TZOO

TZOO has sky rocketed post earnings. There are many other stocks like this. Earnings act as catalyst and there are numerous studies to show effect of earnings and earnings surprises on future price moment. It is easy to build a system based on earning as catalyst.
The earning season always brings out new surprises and as a consequence new stock ideas. Stocks react to earnings immediately in cases where there is a surprise or stock is not followed by most of the analyst. This can set up rallies which last from 6 weeks to sometime years. On the short side also you will find stocks reacting up to 25% post earning.
These trends are not only short lived but have legs. Many of these stocks go on to make triple digits in just few quarters. The breakouts following earnings are some of the most powerful breakouts you will ever see. Some of these stocks just take off like rockets. The overall market direction does not matter.
Obviously with over 7000 stocks reporting earnings, you need some systematic way to reduce the universe to track earnings on, you need your own database to track it and covert it in to proper system using risks management and stops.

Update : You can find more about this here Tops or bottoms- it's a stock pickers market