A speculative Substack scenario by a small research shop sent Wall Street into a jittery tailspin this week, revealing not how real the threat is, but how fragile investor psychology has become around AI futures.
In the last 48 hours, US markets have flipped from shrugging at tariffs and macro uncertainty to skidding on a narrative shove from the most unlikely source: a Substack think piece.
It’s a speculative “Scenario, Not A Prediction” by Citrini Research- envisioning autonomous AI agents stripping friction from the economy, decimating white-collar workforces, and triggering defaults and a mortgage crisis.
The piece didn’t just spark debate; it moved markets.
Stocks in Uber, Mastercard, DoorDash, and American Express slumped sharply after the piece went viral, dragging the software index to depths not seen since last April’s tariff storm.
Let’s be clear: this isn’t a polished academic forecast.
Economists from multiple corners have blasted the logic as incoherent and fear-driven, pointing out that ghost GDP is a contradiction in terms and that consumption can’t collapse without systemic collapse in output. Others call it a thought experiment that crystallized long-standing anxieties about automation and labour displacement.
But what’s truly striking isn’t the likelihood of the doomsday chain reaction. It’s how deeply ingrained AI’s fear of itself has become in market psychology. A small player’s blog post, painting a dystopian feedback loop with “no brake,” has proven enough to turn billions in valuations on a dime.
That tells you something about the emotional wiring of today’s investors: comfort with uncertainty has shrunk, and narratives, especially apocalyptic ones, have outsized influence.
Whether AI tanks the economy in 2028 or simply reshapes industries remains an open question. What’s no longer theoretical is that ideas about AI can ripple through markets as powerfully as earnings reports or central bank moves- a market reflex that might be worth worrying about in its own right.
