AGG vs TLT: Correlation
Measured on weekly returns over the past three years, iShares Core US Aggregate Bond ETF (AGG) and iShares 20+ Year Treasury Bond ETF (TLT) carry a correlation of 0.96, a very strong link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are AGG and TLT?
On 3 years of weekly data the AGG/TLT correlation comes out at 0.96, very strong, meaning they move nearly in lockstep. The relationship has been stable: the 1-year correlation (0.93) sits close to the 3-year figure. The 5-year figure is 0.93, and annualized covariance runs at 68.3 %².
Within AGG's tracked universe of 34 assets, TLT comes in at #4 by 3-year correlation. Neither side won the trailing year by much: +2.3% against +0.3%. The rolling one-year correlation stayed in a tight band between 0.91 and 0.98 over the past three years, which points to a structural rather than episodic relationship. Risk is not evenly split, since TLT carries 2.5 times the volatility of the other side.
How is this computed?
Pearson correlation on weekly returns: ρ(A,B) = cov(rA, rB) / (σA · σB), over windows of 52, 156 and 260 weeks. Covariance is annualized (×52) and expressed in %². Full definitions on the methodology page.
AGG vs TLT: side by side
| AGG (iShares Core US Aggregate Bond ETF) | TLT (iShares 20+ Year Treasury Bond ETF) | |
|---|---|---|
| 1-year return | +2.3% | +0.3% |
| 5-year return | -1.1% | -34.0% |
| Volatility (ann.) | 5.3% | 13.5% |
| Beta vs S&P 500 | 0.07 | 0.11 |
| Max drawdown (3Y) | -4.8% | -14.8% |
| Dividend yield | 4.05% | 4.75% |
| Expense ratio | 0.03% | 0.15% |
| Assets under management | $137.1B | $41.5B |
| Sector / category | ETF · Bonds | ETF · Bonds |
AGG is an Intermediate Core Bond fund from iShares: $137.1B under management, a 0.03% expense ratio, a 4.05% trailing dividend yield. On the fund side, TLT sits in the Long Government category at iShares, with $41.5B under management, a 0.15% expense ratio, a 4.75% trailing dividend yield.
Year-by-year returns
| Year | AGG | TLT |
|---|---|---|
| 2022 | -13.0% | -31.2% |
| 2023 | +5.7% | +2.8% |
| 2024 | +1.3% | -8.1% |
| 2025 | +7.2% | +4.2% |
| 2026 | +0.3% | -2.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are AGG and TLT good diversifiers for each other?
No. With a correlation of 0.96, AGG and TLT move nearly in lockstep, so holding both adds very little diversification.
FAQ
What is the correlation between AGG and TLT?
The AGG/TLT correlation stands at 0.96 on a 3-year window (1 year: 0.93, 5 years: 0.93), computed from weekly returns as of 2026-08-27.
Is TLT a good diversifier for AGG?
No. With a correlation of 0.96, AGG and TLT move nearly in lockstep, so holding both adds very little diversification.
What does a correlation of 0.96 mean?
Correlation ranges from −1 to +1. Values near +1 mean two assets move together, near 0 that they move independently, and negative values that they tend to move in opposite directions. It measures co-movement, not performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/agg-vs-tlt.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/agg-vs-tlt/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: AGG correlations · TLT correlations
