Mostly green. The S&P 500 added 0.7% to close at 7,676.77. The Nasdaq jumped 0.82% — its best session in more than a month — after Anthropic, the company behind the Claude AI models, filed its IPO prospectus with the SEC. The Dow gained 0.28%. Seven of eleven sectors finished positive, with health care flat and communication services the clear laggard at minus 1.6%.

Technology led the board, up 1.7%, followed by industrials at 1.4%. The Anthropic filing lit up the semiconductor and optical names: Lumentum surged 10.6%, Coherent added 7.3%, Synopsys gained 5.8%, and Intel tacked on 5.8%. Tesla jumped 6.6% and pulled consumer discretionary up 1.0%.

On the losing side, Fair Isaac cratered 15.9% — the worst day in the S&P 500 by a wide margin. Charter Communications dropped 4.4%, Omnicom shed 4.2%, and PayPal fell 3.6%.

Oil gave the market some breathing room. WTI crude pulled back to around $101.50, down about 1.7% from Friday's six-month high near $103. That helped. Last week, the oil spike did more damage to sentiment than any earnings miss.

The Nasdaq gained 0.82% the same week it was supposed to keep rolling over. That tells you the AI trade has a floor — and the floor has a name.

Here's what happened. Anthropic filed its public offering paperwork over the weekend. The bankers leading the deal — Goldman, JPMorgan, Morgan Stanley — have told investors the company could go public at a valuation near $2 trillion. That would make it the largest IPO in history, bigger than SpaceX's listing back in June.

Let that land. For two straight weeks, the market punished Microsoft, Meta, Nvidia, and Alphabet for spending too much on AI. The story since mid-October was simple: the checks are getting written, but nobody's seeing the return. Then a company that builds the AI itself — not the chips, not the cloud, but the models — walks into the room and says it's worth $2 trillion.

There's a term for this. When money rotates within a theme — not out of it, but from one part to another — Wall Street calls it a rotation within the trade. The AI trade isn't dying. It's shifting. In 2000, the internet rotation went from the builders (Cisco, Sun Microsystems) to the platforms (Amazon, eBay). This time it's going the other direction — from the infrastructure buyers to the model builders. Whether that sticks depends on what happens in the next four days.

Three of the biggest earnings reports of the year land this week. Microsoft and Alphabet report Wednesday evening. Amazon follows Thursday. These three companies are writing the biggest checks in AI — hundreds of billions combined on data centers, chips, and cloud capacity. If the market is repricing AI around the builders, these reports will test whether the buyers deserve to keep their premium too. The forward guidance on AI revenue — not AI spending — is the only number that matters.

And layered on top of that: the Fed announces its rate decision Wednesday afternoon, and both the Q3 GDP advance estimate and the PCE inflation report come out Thursday morning at 8:30 AM. That's the trifecta. Earnings, rates, and inflation data — all in 48 hours.

That's what this week will do. If Microsoft shows AI revenue growth on Wednesday night and the PCE print stays under 0.3% month-over-month on Thursday, the S&P is going back to its October high near 7,845. If the capex numbers scare the market again and inflation runs hot, the rotation away from tech resumes and the Dow leads into year-end.

I've seen weeks like this before. October 2018 had a similar pileup: a Fed meeting, a GDP print, and the heart of earnings season all in the same window. Stocks swung 3% in either direction on consecutive days. The week didn't resolve the market's bigger question. It just drew the battle lines for the next three months.

Three things I'm watching this week:

The market is pricing a 90% chance the Fed holds rates steady on Wednesday. Nobody expects a hike. But the press conference is what matters. The question is December. Oil is back above $100. The CPI came in at 3.7% two weeks ago. If the Fed signals that a December hike is on the table, the 10-year yield pushes back above 5% and the equity rally from today gives it all back. Watch the language about inflation progress — or the lack of it.

This is the week that makes or breaks the AI spending narrative. Microsoft and Alphabet report after the close Wednesday. Amazon follows Thursday. Last week, four mega-caps beat estimates and all four got sold. The market has already told you a beat isn't enough. It wants forward guidance on AI monetization — proof that the hundreds of billions going into data centers are coming back as revenue. If the numbers show progress, the rotation we saw today accelerates. If the guidance disappoints, the "beat and sell" pattern from last week picks up right where it left off.

The Q3 GDP advance estimate and the Fed's preferred inflation measure both arrive the same morning. GDP is the growth check. The economy has been running hotter than expected all year. If the number comes in above 3%, it keeps the "no recession" camp in the driver's seat — but it also keeps the Fed hawkish. The PCE is the inflation check. Core PCE above 0.3% month-over-month gives the hawks more ammunition for December. Below 0.2% and the whole rate story softens. Two numbers, one morning, and both feed straight into the December meeting.

The Anthropic filing lit the match today. What happens between Wednesday afternoon and Thursday morning tells you whether the fire spreads or burns out.

That's it for today. See you tomorrow after the close.