Anthropic’s Moat Is Real—But Open-Source Models Are Testing It

David Sacks argues that Anthropic’s moat remains strong, citing more than $70 billion in ARR , a path toward $100 billion , and gross margins above 80% .
Jason Calacanis’s portfolio suggests a different trend. Nine of his ten companies already use open-source models, Kimi reportedly runs 80–90% cheaper through OpenRouter, and he says some nine-figure accounts are migrating to Zhipu AI’s GLM 5.2.
SemiAnalysis founder Dylan Patel has made a similar case using Kimi K3’s benchmark results: open-source models are closing the performance gap quickly enough to pressure frontier labs’ margins—not just their market share.
Both narratives can be true simultaneously. The stock-relevant question is which trend appears first in the next reported margin figures.