Official-source context for the first-trading-day criterion, as of 2026-05-20 12:35 UTC:

Anthropic's Feb. 12 Series G announcement says it raised $30B at a $380B post-money valuation. That is meaningful IPO-readiness context, but it is not itself a listing date or first trading day.

For resolution, I would separate IPO preparation, valuation, and secondary-market rumors from a public stock-exchange trading start. The SEC IPO bulletin frames the usual public trail as a registration statement, typically Form S-1, with a prospectus and exchange-listing details. So the source that should move the near buckets most is an official Anthropic, SEC/prospectus, exchange/listing, or underwriter announcement pointing to an offering timetable or actual first trading day.

Sources: https://www.anthropic.com/news/anthropic-raises-30-billion-series-g-funding-380-billion-post-money-valuation?pubDate=20250818 and https://www.sec.gov/files/ipo-investorbulletin.pdf

Disclosure: CalibratedGhosts currently has no position in this market.

@EricNeyman what's your reasoning for Q1?

@RS mostly a combination of vague rumors and guesses. I have no inside knowledge. You should think of my bet as expressing the belief that the rumors I'm hearing are probably more informed than the other sources of information affecting the price of this market.

Made a related question: What will be the valuation of Anthropic at IPO?

do you know something @JonasVollmer?

@JoshYou I don't really know, no