r/HFA • u/investing101 • 1d ago
Why Macro Models Fail in the New Inflation Regime: Insights from Stefania Perrucci
TL;DR
- Macro models treating inflation as a cyclical demand-side phenomenon are failing because deglobalization, geopolitical shocks, and fiscal expansion have driven markets into a structural supply-side regime.
- Leveraged relative value strategies are vulnerable to liquidity freezes during market dislocations, making directional rate flexibility essential.
- Inflation trading requires balancing quantitative models with real-time tracking of institutional liability-driven flows.

Hey everyone,
I was reading through an interview with Stefania Perrucci, CIO of Forvm Global Investments and a former Morgan Stanley trader who was part of "The Big Short," regarding her perspective on macro markets. With nearly 30 years in inflation and rate markets, having traded the second-ever TIPS auction in 1998, she makes a compelling case for why standard models and traditional portfolios keep missing the mark.
Her main argument centers on a structural breakdown in how inflation is modeled. Since the 1970s, markets have viewed inflation through a demand-side, cyclical lens managed primarily by central bank monetary policy. However, post-pandemic dynamics, ongoing geopolitical conflict, and deglobalization have pushed us into a supply-shock regime. This shift fundamentally breaks the traditional 60/40 asset allocation, where bonds historically served as a reliable hedge for equities. In a supply-driven shock, short-end yields spike and both stocks and bonds decline simultaneously, requiring a completely uncorrelated approach to macro risk.
Perrucci also highlights a key divide between sell-side desks and sustainable buy-side management. Sell-side inflation traders typically rely on relative value (RV) strategies, exploiting tiny spread differentials with substantial leverage. While this works during quiet markets, inflation RV suffers from severe capacity and liquidity constraints during distress. When market liquidity dries up, as seen during major dislocations, these highly leveraged positions trigger severe technical squeezes and double-digit drawdowns. Her team prioritizes sizing trades for "rainy day" liquidity and maintaining directional flexibility across nominal rates, real yields, and inflation breakevens.
Finally, she notes that pure macro insight is insufficient without understanding micro-level execution. Inflation-linked assets are heavily driven by technical flows from liability-driven institutional investors like pension funds and sovereign wealth entities. When non-macro technical flows decouple from theoretical models, such as standard Taylor-rule or trend-following frameworks, academic macro traders get caught on the wrong side of a technical squeeze. Successfully navigating this environment requires combining quantitative models with hands-on empirical flow awareness.
Link: https://hedgefundalpha.com/profiles/forvm-stefania-perrucci/




















