VLGIX vs. LTUSX

Last updated Jun 25, 2026

VLGIX (Vanguard Long-Term Treasury Index Fund Institutional Shares) and LTUSX (Thornburg Limited Term U.S. Government Fund) are both Government Bonds funds. Over the past 10 years, VLGIX returned -1.15%/yr vs 0.98%/yr for LTUSX. A 0.73 correlation means they provide meaningful diversification when combined. VLGIX charges 0.05%/yr vs 0.92%/yr for LTUSX.

Performance

VLGIX vs. LTUSX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Long-Term Treasury Index Fund Institutional Shares (VLGIX) and Thornburg Limited Term U.S. Government Fund (LTUSX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, VLGIX achieves a 0.33% return, which is significantly higher than LTUSX's 0.31% return. Over the past 10 years, VLGIX has underperformed LTUSX with an annualized return of -1.15%, while LTUSX has yielded a comparatively higher 0.98% annualized return.

VLGIX

• 1D: 0.21%
• 1M: 2.18%
• YTD: 0.33%
• 6M: -0.09%
• 1Y: 3.49%
• 3Y*: -0.59%
• 5Y*: -5.51%
• 10Y*: -1.15%

LTUSX

• 1D: 0.08%
• 1M: 0.26%
• YTD: 0.31%
• 6M: 0.37%
• 1Y: 3.51%
• 3Y*: 3.65%
• 5Y*: 0.71%
• 10Y*: 0.98%

*Multi-year figures are annualized to reflect compound growth (CAGR)

VLGIX vs. LTUSX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VLGIX Vanguard Long-Term Treasury Index Fund Institutional Shares	0.33%	5.46%	-6.11%	3.67%	-29.45%	-5.06%	17.72%	14.31%	-1.59%	8.64%
LTUSX Thornburg Limited Term U.S. Government Fund	0.31%	6.40%	2.40%	3.40%	-8.06%	-1.82%	3.77%	3.61%	0.98%	0.60%

Correlation

The correlation between VLGIX and LTUSX is 0.80, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.80
Correlation (3Y) Calculated over the trailing 3-year period	0.84
Correlation (5Y) Calculated over the trailing 5-year period	0.82
Correlation (10Y) Calculated over the trailing 10-year period	0.76
Correlation (All Time) Calculated using the full available price history since Nov 23, 2009	0.73

The correlation between VLGIX and LTUSX shifts across timeframes, from 0.73 (all time) to 0.84 (3 years), reflecting how their relationship changes across market environments.

Return for Risk

VLGIX vs. LTUSX — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

VLGIX

VLGIX Risk / Return Rank: 7
VLGIX Sharpe Ratio Rank: 7
VLGIX Sortino Ratio Rank: 6
VLGIX Omega Ratio Rank: 6
VLGIX Calmar Ratio Rank: 7
VLGIX Martin Ratio Rank: 7

LTUSX

LTUSX Risk / Return Rank: 26
LTUSX Sharpe Ratio Rank: 28
LTUSX Sortino Ratio Rank: 29
LTUSX Omega Ratio Rank: 27
LTUSX Calmar Ratio Rank: 26
LTUSX Martin Ratio Rank: 21

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

VLGIX vs. LTUSX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Long-Term Treasury Index Fund Institutional Shares (VLGIX) and Thornburg Limited Term U.S. Government Fund (LTUSX). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.

Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.

	VLGIX	LTUSX	Difference
Sharpe ratio: Return per unit of total volatility	0.48	1.30	-0.82
Sortino ratio: Return per unit of downside risk	0.75	1.94	-1.19
Omega ratio: Gain probability vs. loss probability	1.08	1.23	-0.15
Calmar ratio: Return relative to maximum drawdown	0.60	1.64	-1.04
Martin ratio: Return relative to average drawdown	1.47	4.39	-2.93

VLGIX vs. LTUSX - Sharpe Ratio Comparison

The current VLGIX Sharpe Ratio is 0.48, which is lower than the LTUSX Sharpe Ratio of 1.30. The chart below compares the historical Sharpe Ratios of VLGIX and LTUSX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Drawdowns

VLGIX vs. LTUSX - Drawdown Comparison

The maximum VLGIX drawdown since its inception was -46.23%, which is greater than LTUSX's maximum drawdown of -12.34%. Use the drawdown chart below to compare losses from any high point for VLGIX and LTUSX.

Drawdown Indicators

	VLGIX	LTUSX	Difference
Max Drawdown Largest peak-to-trough decline	-46.23%	-12.34%	-33.89%
Max Drawdown (1Y) Largest decline over 1 year	-6.99%	-2.31%	-4.68%
Max Drawdown (3Y) Largest decline over 3 years	-17.65%	-3.69%	-13.96%
Max Drawdown (5Y) Largest decline over 5 years	-41.00%	-11.69%	-29.31%
Max Drawdown (10Y) Largest decline over 10 years	-46.23%	-12.34%	-33.89%
Current Drawdown Current decline from peak	-36.06%	-1.66%	-34.40%
Average Drawdown Average peak-to-trough decline	-15.10%	-1.40%	-13.70%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.83%	0.86%	+1.97%

Volatility

VLGIX vs. LTUSX - Volatility Comparison

Vanguard Long-Term Treasury Index Fund Institutional Shares (VLGIX) has a higher volatility of 2.12% compared to Thornburg Limited Term U.S. Government Fund (LTUSX) at 0.93%. This indicates that VLGIX's price experiences larger fluctuations and is considered to be riskier than LTUSX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VLGIX	LTUSX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.12%	0.93%	+1.19%
Volatility (6M) Calculated over the trailing 6-month period	6.13%	2.13%	+4.00%
Volatility (1Y) Calculated over the trailing 1-year period	8.68%	2.90%	+5.78%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	14.52%	4.03%	+10.49%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	13.70%	3.09%	+10.61%

VLGIX vs. LTUSX - Expense Ratio Comparison

VLGIX has a 0.05% expense ratio, which is lower than LTUSX's 0.92% expense ratio.

Dividends

VLGIX vs. LTUSX - Dividend Comparison

VLGIX's dividend yield for the trailing twelve months is around 4.56%, more than LTUSX's 2.63% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
LTUSX Thornburg Limited Term U.S. Government Fund	2.63%	2.69%	2.62%	1.89%	1.63%	1.21%	1.35%	1.77%	1.90%	1.45%	2.52%	1.50%
VLGIX Vanguard Long-Term Treasury Index Fund Institutional Shares	4.56%	4.43%	4.67%	3.31%	2.83%	1.78%	2.15%	2.46%	2.73%	2.57%	2.70%	2.82%

Frequently Asked Questions

Can I hold both VLGIX and LTUSX in my portfolio?

VLGIX and LTUSX have a correlation of 0.80, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, VLGIX or LTUSX?

VLGIX has higher volatility (2.12%) compared to LTUSX (0.93%). In terms of maximum drawdown, VLGIX dropped -46.23% vs LTUSX's -12.34%.

Which has better risk-adjusted returns?

LTUSX currently has the higher Sharpe Ratio (1.30 vs 0.48), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.