TSSIX vs. THIMX

Last updated Jun 4, 2026

TSSIX (Thornburg Strategic Municipal Income Fund) and THIMX (Thornburg Intermediate Municipal Fund) are both Municipal Bonds funds from Thornburg. Over the past 10 years, TSSIX returned 2.18%/yr vs 2.00%/yr for THIMX. Their correlation of 0.87 suggests significant overlap in exposure. TSSIX charges 0.59%/yr vs 0.77%/yr for THIMX.

Performance

TSSIX vs. THIMX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Thornburg Strategic Municipal Income Fund (TSSIX) and Thornburg Intermediate Municipal Fund (THIMX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, TSSIX achieves a 1.92% return, which is significantly higher than THIMX's 1.61% return. Over the past 10 years, TSSIX has outperformed THIMX with an annualized return of 2.18%, while THIMX has yielded a comparatively lower 2.00% annualized return.

TSSIX

• 1D: 0.21%
• 1M: 0.79%
• YTD: 1.92%
• 6M: 1.98%
• 1Y: 6.60%
• 3Y*: 5.11%
• 5Y*: 1.65%
• 10Y*: 2.18%

THIMX

• 1D: 0.15%
• 1M: 0.68%
• YTD: 1.61%
• 6M: 1.77%
• 1Y: 6.42%
• 3Y*: 4.48%
• 5Y*: 1.60%
• 10Y*: 2.00%

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

TSSIX vs. THIMX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
TSSIX Thornburg Strategic Municipal Income Fund	1.92%	5.62%	3.77%	5.51%	-8.30%	1.50%	4.03%	5.99%	1.04%	4.21%
THIMX Thornburg Intermediate Municipal Fund	1.61%	5.97%	2.45%	4.88%	-6.63%	1.00%	3.81%	5.86%	0.70%	3.61%

Correlation

The correlation between TSSIX and THIMX is 0.86, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.86
Correlation (3Y) Calculated over the trailing 3-year period	0.90
Correlation (5Y) Calculated over the trailing 5-year period	0.90
Correlation (10Y) Calculated over the trailing 10-year period	0.89
Correlation (All Time) Calculated using the full available price history since Apr 2, 2009	0.87

The correlation between TSSIX and THIMX has been stable across timeframes, ranging from 0.86 to 0.90 - a consistent structural relationship.

Return for Risk

TSSIX vs. THIMX — Risk / Return Rank

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

TSSIX

TSSIX Risk / Return Rank: 70
TSSIX Sharpe Ratio Rank: 77
TSSIX Sortino Ratio Rank: 87
TSSIX Omega Ratio Rank: 92
TSSIX Calmar Ratio Rank: 48
TSSIX Martin Ratio Rank: 47

THIMX

THIMX Risk / Return Rank: 74
THIMX Sharpe Ratio Rank: 88
THIMX Sortino Ratio Rank: 94
THIMX Omega Ratio Rank: 96
THIMX Calmar Ratio Rank: 49
THIMX Martin Ratio Rank: 46

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.

TSSIX vs. THIMX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Thornburg Strategic Municipal Income Fund (TSSIX) and Thornburg Intermediate Municipal Fund (THIMX). 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.

	TSSIX	THIMX	Difference
Sharpe ratio: Return per unit of total volatility	2.54	2.87	-0.33
Sortino ratio: Return per unit of downside risk	4.17	4.84	-0.67
Omega ratio: Gain probability vs. loss probability	1.68	1.81	-0.13
Calmar ratio: Return relative to maximum drawdown	2.63	2.67	-0.04
Martin ratio: Return relative to average drawdown	9.78	9.57	+0.21
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

TSSIX vs. THIMX - Sharpe Ratio Comparison

The current TSSIX Sharpe Ratio is 2.54, which is comparable to the THIMX Sharpe Ratio of 2.87. The chart below compares the historical Sharpe Ratios of TSSIX and THIMX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	TSSIX	THIMX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.54	2.87	-0.33
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.46	0.50	-0.04
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.63	0.61	+0.02
Sharpe Ratio (All Time) Calculated using the full available price history	1.34	1.40	-0.07

Drawdowns

TSSIX vs. THIMX - Drawdown Comparison

The maximum TSSIX drawdown since its inception was -12.64%, which is greater than THIMX's maximum drawdown of -10.22%. Use the drawdown chart below to compare losses from any high point for TSSIX and THIMX.

Drawdown Indicators

	TSSIX	THIMX	Difference
Max Drawdown Largest peak-to-trough decline	-12.64%	-10.22%	-2.42%
Max Drawdown (1Y) Largest decline over 1 year	-2.46%	-2.39%	-0.07%
Max Drawdown (3Y) Largest decline over 3 years	-4.67%	-4.32%	-0.35%
Max Drawdown (5Y) Largest decline over 5 years	-12.64%	-10.22%	-2.42%
Max Drawdown (10Y) Largest decline over 10 years	-12.64%	-10.22%	-2.42%
Current Drawdown Current decline from peak	0.00%	-0.29%	+0.29%
Average Drawdown Average peak-to-trough decline	-1.98%	-1.33%	-0.65%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.66%	0.66%	0.00%

Volatility

TSSIX vs. THIMX - Volatility Comparison

Thornburg Strategic Municipal Income Fund (TSSIX) has a higher volatility of 0.91% compared to Thornburg Intermediate Municipal Fund (THIMX) at 0.80%. This indicates that TSSIX's price experiences larger fluctuations and is considered to be riskier than THIMX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	TSSIX	THIMX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.91%	0.80%	+0.11%
Volatility (6M) Calculated over the trailing 6-month period	1.85%	1.66%	+0.19%
Volatility (1Y) Calculated over the trailing 1-year period	2.55%	2.22%	+0.33%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	3.62%	3.25%	+0.37%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	3.48%	3.28%	+0.20%

TSSIX vs. THIMX - Expense Ratio Comparison

TSSIX has a 0.59% expense ratio, which is lower than THIMX's 0.77% expense ratio.

Dividends

TSSIX vs. THIMX - Dividend Comparison

TSSIX's dividend yield for the trailing twelve months is around 4.13%, more than THIMX's 3.68% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
THIMX Thornburg Intermediate Municipal Fund	3.68%	4.82%	4.03%	2.60%	2.40%	2.25%	2.39%	2.62%	2.48%	2.18%	2.04%	2.08%
TSSIX Thornburg Strategic Municipal Income Fund	4.13%	5.27%	4.42%	2.86%	2.48%	2.08%	2.61%	2.95%	2.76%	2.65%	2.40%	2.63%

Frequently Asked Questions

Can I hold both TSSIX and THIMX in my portfolio?

TSSIX and THIMX have a correlation of 0.86, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, TSSIX or THIMX?

TSSIX has higher volatility (0.91%) compared to THIMX (0.80%). In terms of maximum drawdown, TSSIX dropped -12.64% vs THIMX's -10.22%.

Which has better risk-adjusted returns?

THIMX currently has the higher Sharpe Ratio (2.87 vs 2.54), 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.