TSUMX vs. FORTX

Last updated Aug 1, 2026

TSUMX (Thornburg Summit Fund Class I) and FORTX (Abraham Fortress Fund) are both Diversified Portfolio funds. Over the past 3 years, TSUMX returned 13.92%/yr vs 10.19%/yr for FORTX. Their 0.71 correlation means they have sometimes moved together and sometimes differently. TSUMX charges 0.70%/yr vs 0.75%/yr for FORTX.

Performance

TSUMX vs. FORTX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Thornburg Summit Fund Class I (TSUMX) and Abraham Fortress Fund (FORTX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, TSUMX achieves a 6.96% return, which is significantly lower than FORTX's 13.07% return.

TSUMX

• 1D: 0.07%
• 1M: -0.13%
• 6M: 2.72%
• YTD: 6.96%
• 1Y: 17.08%
• 3Y*: 13.92%
• 5Y*: 8.29%
• 10Y*: —
• ALL TIME*: 12.16%

FORTX

• 1D: 0.24%
• 1M: 0.00%
• 6M: 5.33%
• YTD: 13.07%
• 1Y: 27.30%
• 3Y*: 10.19%
• 5Y*: —
• 10Y*: —
• ALL TIME*: 7.29%

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

Liquidity Comparison

Position	Avg. Volume Value (2W)	Avg. Volume Value (1M)	Avg. Volume Value (3M)
FORTX Abraham Fortress Fund	$0.00	$0.00	$0.00
TSUMX Thornburg Summit Fund Class I	$0.00	$0.00	$0.00

TSUMX vs. FORTX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021
TSUMX Thornburg Summit Fund Class I	6.96%	20.51%	11.42%	12.31%	-9.79%	2.50%
FORTX Abraham Fortress Fund	13.07%	9.40%	7.45%	10.51%	-6.32%	1.81%

Correlation

The correlation between TSUMX and FORTX is 0.63, which is moderate. They have sometimes moved together and sometimes differently, sharing some price drivers without tracking each other closely.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.63
Correlation (3Y) Balances recent behavior with more history.	0.68
Correlation (All Time) Calculated using the full available price history since Oct 14, 2021	0.72

The correlation between TSUMX and FORTX has been stable across timeframes, ranging from 0.63 to 0.71 - a consistent structural relationship.

Return for Risk

TSUMX vs. FORTX — Risk / Return Rank

Compare historical risk-adjusted metric ranks over the past 12 months.

TSUMX

TSUMX Risk / Return Rank: 76
TSUMX Sharpe Ratio Rank: 80
TSUMX Sortino Ratio Rank: 76
TSUMX Omega Ratio Rank: 77
TSUMX Calmar Ratio Rank: 77
TSUMX Martin Ratio Rank: 70

FORTX

FORTX Risk / Return Rank: 93
FORTX Sharpe Ratio Rank: 94
FORTX Sortino Ratio Rank: 92
FORTX Omega Ratio Rank: 87
FORTX Calmar Ratio Rank: 96
FORTX Martin Ratio Rank: 95

The rank (0–100) uses a weighted average of the Sharpe, Sortino, Omega, Calmar, and Martin percentile ranks for the trailing 12 months. Higher means stronger historical risk-adjusted performance within the peer group.

TSUMX vs. FORTX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Thornburg Summit Fund Class I (TSUMX) and Abraham Fortress Fund (FORTX). 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.

	TSUMX	FORTX	Difference
Sharpe ratio: Return per unit of total volatility	1.92	2.53	-0.61
Sortino ratio: Return per unit of downside risk	2.67	3.55	-0.88
Omega ratio: Gain probability vs. loss probability	1.35	1.45	-0.09
Calmar ratio: Return relative to maximum drawdown	2.58	4.67	-2.09
Martin ratio: Return relative to average drawdown	8.96	15.61	-6.66

TSUMX vs. FORTX - Sharpe Ratio Comparison

The current TSUMX Sharpe Ratio is 1.92, which is comparable to the FORTX Sharpe Ratio of 2.53. The chart below compares the historical Sharpe Ratios of TSUMX and FORTX, 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

TSUMX vs. FORTX - Drawdown Comparison

The maximum TSUMX drawdown since its inception was -28.87%, which is greater than FORTX's maximum drawdown of -13.77%. Use the drawdown chart below to compare losses from any high point for TSUMX and FORTX.

Drawdown Indicators

	TSUMX	FORTX	Difference
Max Drawdown Largest peak-to-trough decline	-28.87%	-13.77%	-15.10%
Max Drawdown (1Y) Largest decline over 1 year	-6.27%	-5.51%	-0.76%
Max Drawdown (3Y) Largest decline over 3 years	-10.37%	-13.77%	+3.40%
Max Drawdown (5Y) Largest decline over 5 years	-28.87%	—	—
Current Drawdown Current decline from peak	-3.11%	-1.50%	-1.61%
Average Drawdown Average peak-to-trough decline	-7.50%	-3.15%	-4.35%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.80%	1.65%	+0.15%

Volatility

TSUMX vs. FORTX - Volatility Comparison

Thornburg Summit Fund Class I (TSUMX) has a higher volatility of 2.26% compared to Abraham Fortress Fund (FORTX) at 2.06%. This indicates that TSUMX's price experiences larger fluctuations and is considered to be riskier than FORTX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	TSUMX	FORTX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.26%	2.06%	+0.20%
Volatility (6M) Calculated over the trailing 6-month period	6.56%	7.08%	-0.52%
Volatility (1Y) Calculated over the trailing 1-year period	8.42%	10.20%	-1.78%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	13.97%	9.39%	+4.58%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	13.62%	9.39%	+4.23%

TSUMX vs. FORTX - Expense Ratio Comparison

TSUMX has a 0.70% expense ratio, which is lower than FORTX's 0.75% expense ratio.

Dividends

TSUMX vs. FORTX - Dividend Comparison

TSUMX's dividend yield for the trailing twelve months is around 6.48%, more than FORTX's 1.47% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019
FORTX Abraham Fortress Fund	1.47%	1.66%	0.00%	1.93%	7.76%	1.61%	0.00%	0.00%
TSUMX Thornburg Summit Fund Class I	6.48%	6.22%	4.86%	2.03%	2.61%	19.21%	5.11%	1.77%

Frequently Asked Questions

Can I hold both TSUMX and FORTX in my portfolio?

TSUMX and FORTX have a correlation of 0.63, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, TSUMX or FORTX?

TSUMX has higher volatility (2.26%) compared to FORTX (2.06%). In terms of maximum drawdown, TSUMX dropped -28.87% vs FORTX's -13.77%.

Which has better risk-adjusted returns?

FORTX currently has the higher Sharpe Ratio (2.53 vs 1.92), 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.