

Stress testing AI’s ‘what if’ scenarios
Author
Olivier d'Assier
Lead Principal Investment Decision Research
SimCorp
Three scenarios facing an AI-tilted portfolio: a volatility spike triggered by AI-driven job losses, a repricing of subscription-based credit, and a reset in AI valuations. Modeled separately, they show how an AI-related shift could travel through a portfolio in different ways, not only through the obvious AI names.
Three scenarios that test how volatility, credit and valuation shifts could move an AI portfolio
AI remains a story of real investment, elevated expectations, and returns that are still unevenly distributed and difficult to predict. The infrastructure is visible across the market, but it holds a very broad valuation premium.
This landscape is sensitive to changes in investor expectations because exposure has become concentrated around a single narrative. In Q2, the Technology sector added another five percentage points to its already dominant weight in the STOXX US index. It now contributes around 63 percent of index volatility, up 13 percentage points from Q1. The US market, and by extension many institutional passive portfolios, has become a partial proxy for the AI trade.
The factor points in the same direction. Medium-term Momentum's return was 1.4 standard deviations above its historical mean, dating back to 1982. Crowding's return was stronger still, at 1.8 standard deviations, albeit on a shorter history. Short Interest, a proxy for hedging demand, was slightly negative at -0.2 standard deviations.
From this data, it’s clear that investors owned the AI trade with conviction and with limited downside protection. This matters because investors have already worked through three distinct AI what-if scenarios:
- What if AI adoption changes labor-market expectations faster than the economy can adjust?
- What if AI changes the economics of software-based business service companies, especially legacy SaaS models, and creates refinancing pressure in parts of the private-credit market?
- What if AI assets are priced for revenues that arrive later than expected?
Each scenario has already appeared in market pricing, yet none has become the base case. The useful question is therefore not whether AI is good or bad. It is how to model each scenario if it re-enters market pricing, so the portfolio is prepared before the narrative moves again.
For illustration, we use a hypothetical Risk-On US portfolio designed to capture the AI theme. The portfolio is overweight Information Technology, Industrials, and Consumer Discretionary. It also has positive exposure to risk-tolerant style factors in Axioma's US5.1 Fundamental Factor risk model: Market Sensitivity, Downside Risk, Residual Volatility, Leverage, Investment, and Profit Growth.
"AI exposure is increasingly concentrated across sectors, factors and credit channels. Firms should stress-test how a shift in investor expectations would transmit through portfolios before the narrative changes."
Prepare the model before the narrative returns
AI exposure is now concentrated across sectors, factors, and credit markets alike. This piece modeled three ways that concentration could break: a labor-market shock, a credit repricing, and a valuation reset. Each has already moved markets once and each can re-enter market pricing quickly because each rests on an unresolved question:
Will AI adoption change labor-market expectations fast enough to affect the macro story? Will AI change software revenue assumptions before leveraged borrowers can refinance? Will AI monetization arrive fast enough to support the valuations already assigned to it?
Firms should stress-test how a shift in investor expectations would transmit through their portfolios before the narrative changes again.
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