Why did Intel stock fall 5.7% on September 28, 2026?

Intel stock fell 5.7% on September 28, 2026, the biggest single drag on any Finforge trading agent that day. Intel Corporation made up 8.6% of the Sophon Apex v3.1 portfolio, so the drop took 0.5% off the agent's return, according to Finforge's daily agent report for September 28, 2026.

Why did Intel stock fall on September 28? The report records the move and the damage, not the cause, and we are not going to invent one. What it does show is the mechanism inside the portfolio. Contribution is the share of a day's return one holding produced, its weight multiplied by its move. Intel moved down 5.7% at a weight of 8.6%, and that arithmetic comes to 0.5%.

INTC stock September 28: how one name set the tone

Intel was not alone on the wrong side. Three more holdings in Sophon Apex fell more than 2% the same day. KKR fell 3.5% and cost the agent 0.3%, Meta Platforms fell 4.8% for 0.3%, and Huntington Bancshares fell 2.2% for 0.3%. Four names dragged the whole agent down.

How Sophon Apex finished against the S&P 500

Sophon Apex v3.1 closed September 28, 2026 at -2.3% for the day. Its benchmark, the Standard and Poor's 500, closed at -0.8% over the same stretch. The gap was 1.5% against the agent.

The same market, different answers

Sophon Core v3.1 rose 0.2% against the same -0.8% for the S&P 500, helped by CrowdStrike, up 2.8% for a contribution of 0.3%. Sophon Surge v3.1 slipped 0.8% and matched the S&P 500, with Sandisk Corporation down 3.7% for 0.4%. We put the laggard next to the leader, because a record that only shows the good days is not a record.

Who publishes these numbers

Finforge runs AI trading agents in public and publishes what they held and how they did, every day, wins and losses. The four Sophon agents trade founder capital in Alpaca paper accounts, not customer money, and they have done so openly since April 21, 2026. Check the live results against the S&P 500 on the Sophon Apex page, and the live results for all four Sophon agents, including the days they lost.

Questions people ask

Why did Intel stock fall on September 28, 2026?

Intel Corporation closed 5.7% lower that day. Finforge's daily agent report records the size of the move and what it did to the portfolio, not the reason. At a weight of 8.6% in Sophon Apex v3.1, the fall produced 0.5% of the agent's return for September 28, 2026.

What does contribution mean in an AI trading agent report?

Contribution is the slice of one day's portfolio return that came from a single position. It combines how much the agent held with how far the stock moved. A stock can fall 5.7% and barely register if the agent holds almost none of it; Intel mattered on September 28, 2026 because Sophon Apex held 8.6% of the portfolio in it.

Do the Sophon agents trade real money?

Not yet. The four agents have traded in public since April 21, 2026, using founder capital in Alpaca paper accounts. Finforge is building a mobile brokerage app with Alpaca's licensed European entity, and the waitlist is the only thing to sign up for right now.

All figures here cover one trading day, September 28, 2026, measured against the benchmark named in each section. Past performance is not a guide to future returns.