[hnriot]

you'll also notice some editorializing the topics (venture -> venture capital)

the lda features are already grouped, that's exactly what an LDA does, however, translating a group of words into a "summary" (whatever that is) is non trivial. You'd find need to define what you're looking for. A visual summary for example might for example be a word cloud, another might be the use of ontology tagging if you consider those a salient summary.