BND vs TLT: Correlation
Vanguard Total Bond Market ETF (BND) and iShares 20+ Year Treasury Bond ETF (TLT) show a very strong relationship: their 3-year correlation of weekly returns is 0.96.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BND and TLT?
Across a 3-year window, the weekly returns of BND and TLT correlate at 0.96, very strong, meaning they move nearly in lockstep. Little has changed lately, as the 1-year reading of 0.93 lands near the 3-year figure. Stretching to 5 years gives 0.93, with an annualized covariance of 67.0 %².
Within BND's tracked universe of 33 assets, TLT comes in at #4 by 3-year correlation. Their 12-month results are close: +2.3% for BND against +0.3% for TLT. The rolling one-year correlation stayed in a tight band between 0.91 and 0.97 over the past three years, which points to a structural rather than episodic relationship. Risk is not evenly split, since TLT carries 2.6 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.
BND vs TLT: side by side
| BND (Vanguard Total Bond Market ETF) | TLT (iShares 20+ Year Treasury Bond ETF) | |
|---|---|---|
| 1-year return | +2.3% | +0.3% |
| 5-year return | -1.3% | -34.0% |
| Volatility (ann.) | 5.2% | 13.5% |
| Beta vs S&P 500 | 0.06 | 0.11 |
| Max drawdown (3Y) | -4.7% | -14.8% |
| Dividend yield | – | 4.75% |
| Expense ratio | – | 0.15% |
| Assets under management | – | $41.5B |
| Sector / category | ETF · Bonds | ETF · Bonds |
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 | BND | TLT |
|---|---|---|
| 2022 | -13.1% | -31.2% |
| 2023 | +5.7% | +2.8% |
| 2024 | +1.4% | -8.1% |
| 2025 | +7.1% | +4.2% |
| 2026 | +0.2% | -2.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are BND and TLT good diversifiers for each other?
No: a correlation of 0.96 means BND and TLT tend to fall together, which is precisely when diversification is supposed to help.
FAQ
What is the correlation between BND and TLT?
The BND/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 BND?
No: a correlation of 0.96 means BND and TLT tend to fall together, which is precisely when diversification is supposed to help.
What does a correlation of 0.96 mean?
A reading of 0.96 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/bnd-vs-tlt.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/bnd-vs-tlt/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: BND correlations · TLT correlations
