Hi there,
I asked quite a few people, including some SEO's from the most prominent financial news publishers in the country. Unfortunately nobody has researched Google Finance at that granular level. It was described as an "algo overlay", using News as the foundation. The best recommendation I can provide is that you could do your own brief analysis of 200-300 stories on Finance, and look for attributes that correlate between them.
Sorry this isn't specifically answering your questions, but we would certainly welcome any research. Good luck!