Curious - what stops an Apple employee working on the App Store from personally investing in an early stage startup that has seen tremendous growth on the App Store? Or similarly from insights on traffic from a Google team member? AFAIK, there is nothing legally that precludes you from doing so...
They sign a contract stating they won't do it when joining Apple.
Needless to say that doesn't work, especially given the number of enforcement officials at the SEC and the capacity there, and the fact that Apple would have to sue it's own employees (plus the fact that you wouldn't want them to be heavy-handed at all).
So SOX means that very few employees can have access to such data. The more enterprising amongst them still do of course - as do the ones that you really don't want to have access to it. The ones that would both "need" the data (not really), and would know exactly how to profit from it - general and financial management.
