Inflation Above 2.4% Erodes Bond Safety as iShares 20+ Year ETF Nears Pre-2008 Levels
TLT•Morgan Stanley analysis of 150 years shows that when inflation exceeds 2.4%, stock-bond correlation turns positive and bonds lose their shock-absorbing role. The iShares 20+ Year Treasury Bond ETF has fallen toward its pre–financial crisis price, trailing both the S&P 500 and Bloomberg Aggregate Bond Index since early 2022.
1. Historical Correlation Analysis
Morgan Stanley analyzed 150 years of data and identified that when inflation exceeds 2.4%, stocks and bonds tend to move in the same direction, reducing the typical negative correlation that cushions portfolios during equity downturns.
2. 60/40 Portfolio Performance Breakdown
Since the end of 2021, the classic 60/40 portfolio has rebounded modestly, with the stock-heavy S&P 500 surging significantly while the Bloomberg Aggregate Bond Index remains flat, illustrating the bond side's lagging recovery.
3. TLT Price Dynamics
The iShares 20+ Year Treasury Bond ETF has slid back to levels last seen before the 2008 financial crisis as rising yields compress bond prices, challenging its role as a reliable diversifier in balanced portfolios.
