1. Event studies look at how the stock market reacts to corporate occurrences. Traders factor in significant legal events.
2. Event studies look at how the stock market reacts to significant corporate occurrences. Significant legal events are factored in by traders.
The first variation starts with event studies and closes with a definition based on “corporate occurrences.” The second sentence does not link to the last point of the preceding sentence – corporate occurrences. It introduces a new notion (traders), before returning to the corporate occurrences idea.
The second variation flows more easily from the corporate occurrences idea at the end of the first sentence to a restatement of it and then to the new idea (traders). Most sentences should early on link to a point made in the preceding sentence and go on to introduce something new, and so forth. I am indebted to George D. Gopen, Expectations: Teaching Writing From The Reader’s Perspective (Pearson Education 2004) for this fundamental pointer on style and logic.