Photo via The Sydney Morning Herald

From fear to greed and back again: AI is taking Wall Street to extremes

Read the original at The Sydney Morning Herald ↗
Cite

Reinicke, C. (2026, September 29). From fear to greed and back again: AI is taking Wall Street to extremes. The Sydney Morning Herald. https://www.smh.com.au/business/markets/from-fear-to-greed-and-back-again-ai-is-taking-wall-street-to-extremes-20260929-p610wy.html?ref=rss&utm_medium=rss&utm_source=rss_feed

Dated when The Aporia collected the article, usually within hours of publication. Check the original for its exact date and byline.

The Sydney Morning Herald · collected 2026-09-29 · by Carmen Reinicke

Quick Summary

Over the past two weeks, Wall Street experienced extreme volatility in AI-related stocks due to shifting narratives around the technology’s risks and potential. On September 12, concerns raised by industry leaders like Anthropic CEO Dario Amodei led to a sharp decline of over $600 billion in market value within days as tech-heavy indexes fell. However, excitement over Meta Platforms’ AI assistant Muse quickly reversed this trend, with the Nasdaq 100 gaining $3 trillion back and hitting new highs by week’s end. This rollercoaster reflects investors' struggle to assess fundamental values amid rapid sentiment changes triggered by AI developments.
Written by AI on 2026-09-29, from this article's own text only (the story summary below draws on all the coverage).

AI analysis

Story summary

In early September, concerns over the risks posed by advanced AI models led to a significant shift in Wall Street's attitude toward AI-related stocks. On September 12, Anthropic CEO Dario Amodei called for a slowdown in AI development, which was echoed by OpenAI’s Sam Altman and SpaceX’s Elon Musk. This triggered immediate market reactions, causing AI infrastructure stocks to plummet as investors feared reduced spending on computing equipment. The Nasdaq 100 Index dropped 1.5% between September 14 and 15, wiping out more than $US20 billion in value. However, the narrative soon shifted from fear of existential risks to optimism about AI’s potential benefits, with investors returning to stocks like Nvidia and Broadcom as their valuations stabilized or improved. Nancy Tengler, CEO at Laffer Tengler Investments, noted that “this has been a narrative market where the story changes every other week,” reflecting the volatility driven by changing perspectives on AI technology's impact.

Written for “AI in Finance Trends” on 2026-11-03, grounded in this article and the 0 other(s) covering the same event.

Story

📰 AI in Finance Trends
Technology · 1 article(s) covering the same event.

Compared with similar articles

This article reads unscored and hedges 16% of its claims. Each row says how that neighbour differs.
Al Jazeera
⚖️ Leans left Hedges 0 of 3 claims Outlet record 60/100
“The articles discuss different aspects of AI's impact and do not describe the same specific incident.”
Semafor
⚖️ Leans left Hedges 1 of 4 claims Outlet record 59/100
“The articles discuss different topics related to AI and technology markets, with Article A focusing on Oracle's data center issues and Article B discussing market volatility in relation to AI stocks.”
The Sydney Morning Herald
Hedges 9 of 53 claims Outlet record 61/100
“The articles discuss different aspects of AI and its impacts on society, with Article A focusing on personal financial advice and Article B on AI's influence on Wall Street and stock market volatility.”
South China Morning Post
⚖️ Leans left Hedges 1 of 5 claims Outlet record 63/100
“The articles discuss different aspects of AI's impact and market reactions, not the same specific incident.”
The Sydney Morning Herald
⚖️ Leans left Hedges 17 of 45 claims Outlet record 61/100
“The articles discuss different aspects of AI and its impacts on finance and personal tasks, without describing the same specific incident.”
Al Jazeera
Hedges 3 of 20 claims Outlet record 60/100
“Article A discusses Bill Gates' views on AI regulation during media appearances, while Article B covers Wall Street's fluctuating reaction to AI developments and investor sentiment.”
AI and social catastrophe Different event
Dawn
⚖️ Leans strongly left Hedges 5 of 34 claims Outlet record 72/100
“The articles discuss different aspects and timeframes related to AI, with Article A focusing on skepticism and societal risks over a year, while Article B covers recent market volatility in Wall Street over the past two weeks.”
Semafor
⚖️ Leans right Hedges 0 of 8 claims Outlet record 59/100
“The articles discuss different aspects of AI's impact and do not refer to the same specific incident or time frame.”
The Guardian
⚖️ Leans left Hedges 12 of 62 claims Outlet record 66/100
“The articles discuss different aspects and timespans related to AI concerns but do not describe the same specific incident.”
New York Post
Hedges 7 of 18 claims Outlet record 66/100
“The articles discuss different aspects and implications of AI on finance, with Article A focusing on potential bank runs caused by AI agents optimizing returns for consumers, while Article B covers broader market volatility and investor sentiment towards AI technologies.”
How this article was measured signals, leaning charts, publisher record, byline, topics and claims

Signals How these are calculated →

Claims extracted
44
sentences that state something as happening or true
Uncertain
16%
7 of 44 hedged ("reportedly", "may", "according to")
Leaning
not political
takes no side on a contested political question
Publisher signals
61/100
The Sydney Morning Herald's corrections and hedging, across everything collected from it. Not a measure of accuracy.
Outlets on this story
1
Technology
Same framing elsewhere
1
articles that frame the event the way this one does
Analyzed 2026-09-29 · how these are computed

How this is being covered How these are calculated →

Article leaning vs. publisher reliability
Source leaning vs. consistency

Publisher

The Sydney Morning Herald · 5874 article(s) · 15 correction(s) detected
Running correction rate · 15 correction(s)

Who wrote this

Carmen Reinicke
1 article(s) here · 1 carrying a prediction
🔮 Artificial intelligence could wipe us all out.
The only article under this byline in the corpus.

Topics

Anthropic Laffer Tengler Investments Meta Platforms’ OpenAI SpaceX

Subjects

Anthropic ORG · 2× Amodei ORG · 1× Dario Amodei PERSON · 1× Elon Musk PERSON · 1× Laffer Tengler Investments ORG · 1× Meta Platforms’ ORG · 1× Nancy Tengler PERSON · 1× OpenAI ORG · 1× Sam Altman PERSON · 1× SpaceX ORG · 1×

Narrative

“You don’t have to believe that this pace of growth is going to continue for five years in order to own companies like Nvidia or Broadcom and some of the others because their valuations have really come in,” said Feeney, whose firm holds shares of both companies.
framing: assertive · carried by 1 article(s) · first seen 2026-09-29
🔮 Artificial intelligence could wipe us all out.
2026-09-29 · The Sydney Morning Herald
From fear to greed and back again: AI is taking Wall Street to extremes · assertive framing

Claims (44 extracted, 7 hedged)

Artificial intelligence could wipe us all out. uncertain
intelligence → wipe → us
Or it might just kill our unwanted subscriptions. uncertain
it → kill → subscriptions
Those are the two extremes Wall Street has swung between over the past two weeks, sending hundreds of billions of dollars sloshing out of – and then back into – AI-exposed stocks while fraying the nerves of investors scrambling to keep up. asserted
Street → swing → investors
“This has been a narrative market and the narrative changes every other week,” said Nancy Tengler, chief executive at Laffer Tengler Investments. asserted
Tengler → change → Investments
It started on September 12, when Anthropic chief executive Dario Amodei called for a slowdown in development of cutting-edge AI models, which was quickly backed by OpenAI chief executive Sam Altman and SpaceX chief executive Elon Musk. asserted
which → start → Altman
The moves seemed to validate a series of recent warnings from within the industry about existential risks posed by the technology. asserted
moves → seem → technology
On the first trading day after Amodei’s essay was published, AI infrastructure stocks tumbled, as investors worried that hitting the brakes on development would mean less spending on computing equipment. asserted
hitting → publish → equipment
The tech-heavy Nasdaq 100 Index dropped 1.5 per cent between September 14 and 15, erasing more than $US600 billion ($850 billion) in market value. asserted
Index → drop → value
But those fears vanished last week as excitement about the popularity of Meta Platforms’ Muse personal assistant sent traders rushing back into AI-exposed stocks. asserted
excitement → vanish → stocks
Meta shares jumped 11 per cent on Monday last week, putting the Facebook and Instagram parent on pace for its best month in more than a decade, after struggling for much of the year amid concerns that heavy spending on AI wouldn’t pay off. asserted
spending → jump → AI
Intel and Advanced Micro Devices each rallied more than 9 per cent. asserted
Intel → rally → ?
The Philadelphia Stock Exchange Semiconductor Index, known by its ticker SOX, gained 6 per cent on Monday and Tuesday last week, helping to push the Nasdaq 100 to its first record since early June. asserted
Index → know → June
It also triggered sell-offs in the shares of companies that rely on recurring bills and negotiable pricing as AI agents are expected to improve at tasks such as price comparison, trip bookings and customer service interactions. asserted
agents → trigger → comparison
Insurer Allstate fell 8.9 per cent for the week, while cable-provider Charter Communications sank 12 per cent and Planet Fitness, 14 per cent. asserted
Communications → fall → cent
Still, by the end of the week, $US3 trillion had been added to the Nasdaq 100 since the September 15 low. asserted
trillion → add → low
“The moves are staggering in both directions,” said Rhys Williams, chief strategist at Wayve Capital Management. asserted
Williams → say → Management
“It’s hard to explain from a fundamental point of view.” asserted
It → ’ → view
Of course, rapid changes in sentiment are nothing new in this market, which has been propelled higher by AI for nearly four years. asserted
which → propel → years
In early 2025, fears about a pullback in spending sparked by a DeepSeek AI model, developed on the cheap in China, caused semiconductor stocks to plunge. asserted
stocks → spark → China
Nvidia, which dominates the market for AI chips, dropped 17 per cent in a single day. asserted
which → dominate → day
those fears proved to be misplaced, AI has only got more important for the market and the economy, with spending from tech giants and AI start-ups ballooning. asserted
spending → prove → giants
And that’s giving investors itchy trigger fingers, especially when it comes to AI disruption. asserted
it → give → disruption
The Muse-driven sell-off had echoes of earlier this year when releases of AI tools from Anthropic sent shares in a broad range of industries tumbling, from software-as-a-service companies to asset managers. asserted
shares → drive → managers
But when it comes to AI spending, investors are grappling with other risks in addition to safety. asserted
investors → come → safety
Interest rates are soaring, making the cost of AI development more expensive. asserted
cost → soar → development
Fears about that flow of money slowing down have been most apparent in semiconductor stocks. asserted
flow → slow → stocks
After doubling from the start of the year through June 22, the SOX tumbled 29 per cent to a July 29 low. asserted
SOX → double → low
While the index has staged a rebound, it remains down 13 per cent from the June peak. asserted
it → stag → peak
The sell-off has knocked a lot of the froth out of stock prices, leaving many of the companies poised for more gains, according to JoAnne Feeney, a portfolio manager at Advisors Capital Management. uncertain
off → knock → Management
“You don’t have to believe that this pace of growth is going to continue for five years in order to own companies like Nvidia or Broadcom and some of the others because their valuations have really come in,” said Feeney, whose firm holds shares of both companies. asserted
firm → have → companies
“We may very well be positioned for renewed interest in the key contributors to the AI infrastructure build-out.” uncertain
We → position → out
Nvidia shares recently hit their cheapest valuation in more than a decade. asserted
shares → hit → decade
At less than 17 times profit expected over the next 12 months, the stock’s multiple is half what it commanded in 2025, according to data compiled by Bloomberg. uncertain
commanded → expect → Bloomberg
Other investors are taking a more cautious approach. asserted
investors → take → approach
Daniel Pilling, a portfolio manager at Sands Capital, still sees plenty of risk in the AI trade, particularly because no one knows what’s in store for the technology. asserted
what → see → technology
“We manage it with a lot of humility in terms of what we can do and what we know,” said Pilling. asserted
Pilling → manage → what
“But net-net I would actually still say that maybe there’s a sense of AI concern, I suppose, rather than sort of that bullishness that we had in May and June.” uncertain
we → say → May
Such scepticism is plentiful and a sign that the market remains healthy, according to Tengler. uncertain
market → remain → Tengler
“What you don’t want is euphoria, which is what we had at the end of the ’90s,” she said, referring to the dotcom bubble. asserted
she → want → bubble
Investors will get the latest read on the outlook for AI spending this week when memory chip maker Micron Technology reports earnings on Wednesday after US markets close [early Thursday AEST]. asserted
markets → get → Wednesday
…and 4 more, not listed.
💬Give feedback
🕘History 🎫Support