Part 1 Fast Trees: Building RAPTOR Retrieval over SEC Filings with a Diffusion LLM
RAPTOR builds a tree of summaries over a filing so that a thematic question, such as Apple's overall posture on supply-chain risk, is answered from a synthesis rather than from whichever chunk happened to rank first. The catch is that every internal node is a summarizer call, run one after another, so the summarizer's speed and price are the budget. This part swaps in Inception's Mercury-2, a diffusion language model, and runs a cold build over Apple's fiscal 2025 10-K to see what that does to the cost math.