CDSRX vs. CULAX

Last updated Jun 4, 2026

CDSRX (Calvert Short Duration Income Fund Class R6) and CULAX (Calvert Ultra-Short Duration Income Fund) are both mutual funds - CDSRX is a Short-Term Bond fund managed by Calvert Research and Management, while CULAX is a Ultrashort Bond fund managed by Calvert Research and Management. Over the past 5 years, CDSRX returned 2.85%/yr vs 3.38%/yr for CULAX. A 0.55 correlation means they provide meaningful diversification when combined. CDSRX charges 0.45%/yr vs 0.72%/yr for CULAX.

Performance

CDSRX vs. CULAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Calvert Short Duration Income Fund Class R6 (CDSRX) and Calvert Ultra-Short Duration Income Fund (CULAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, CDSRX achieves a 0.82% return, which is significantly lower than CULAX's 1.34% return.

CDSRX

• 1D: 0.00%
• 1M: 0.38%
• YTD: 0.82%
• 6M: 1.22%
• 1Y: 4.82%
• 3Y*: 5.80%
• 5Y*: 2.85%
• 10Y*: —

CULAX

• 1D: 0.00%
• 1M: 0.31%
• YTD: 1.34%
• 6M: 1.77%
• 1Y: 4.21%
• 3Y*: 5.11%
• 5Y*: 3.38%
• 10Y*: 2.47%

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

CDSRX vs. CULAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019
CDSRX Calvert Short Duration Income Fund Class R6	0.82%	6.35%	5.74%	6.87%	-5.07%	1.20%	4.82%	4.87%
CULAX Calvert Ultra-Short Duration Income Fund	1.34%	4.55%	5.69%	6.07%	-0.56%	0.43%	0.66%	2.62%

Correlation

The correlation between CDSRX and CULAX is 0.50, 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	0.50
Correlation (3Y) Calculated over the trailing 3-year period	0.55
Correlation (5Y) Calculated over the trailing 5-year period	0.57
Correlation (All Time) Calculated using the full available price history since Feb 8, 2019	0.55

The correlation between CDSRX and CULAX has been stable across timeframes, ranging from 0.50 to 0.57 - a consistent structural relationship.

Return for Risk

CDSRX vs. CULAX — Risk / Return Rank

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

CDSRX

CDSRX Risk / Return Rank: 71
CDSRX Sharpe Ratio Rank: 61
CDSRX Sortino Ratio Rank: 88
CDSRX Omega Ratio Rank: 80
CDSRX Calmar Ratio Rank: 65
CDSRX Martin Ratio Rank: 63

CULAX

CULAX Risk / Return Rank: 98
CULAX Sharpe Ratio Rank: 94
CULAX Sortino Ratio Rank: 100
CULAX Omega Ratio Rank: 99
CULAX Calmar Ratio Rank: 99
CULAX Martin Ratio Rank: 99

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.

CDSRX vs. CULAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Calvert Short Duration Income Fund Class R6 (CDSRX) and Calvert Ultra-Short Duration Income Fund (CULAX). 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.

	CDSRX	CULAX	Difference
Sharpe ratio: Return per unit of total volatility	2.30	3.22	-0.92
Sortino ratio: Return per unit of downside risk	4.29	11.38	-7.10
Omega ratio: Gain probability vs. loss probability	1.53	4.15	-2.62
Calmar ratio: Return relative to maximum drawdown	3.10	13.98	-10.88
Martin ratio: Return relative to average drawdown	12.37	56.95	-44.59
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

CDSRX vs. CULAX - Sharpe Ratio Comparison

The current CDSRX Sharpe Ratio is 2.30, which is comparable to the CULAX Sharpe Ratio of 3.22. The chart below compares the historical Sharpe Ratios of CDSRX and CULAX, 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

	CDSRX	CULAX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.30	3.22	-0.92
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	1.19	2.53	-1.34
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	1.75	—
Sharpe Ratio (All Time) Calculated using the full available price history	1.29	2.07	-0.78

Drawdowns

CDSRX vs. CULAX - Drawdown Comparison

The maximum CDSRX drawdown since its inception was -9.96%, which is greater than CULAX's maximum drawdown of -7.40%. Use the drawdown chart below to compare losses from any high point for CDSRX and CULAX.

Drawdown Indicators

	CDSRX	CULAX	Difference
Max Drawdown Largest peak-to-trough decline	-9.96%	-7.40%	-2.56%
Max Drawdown (1Y) Largest decline over 1 year	-1.56%	-0.30%	-1.26%
Max Drawdown (3Y) Largest decline over 3 years	-1.56%	-0.30%	-1.26%
Max Drawdown (5Y) Largest decline over 5 years	-7.91%	-2.19%	-5.72%
Max Drawdown (10Y) Largest decline over 10 years	—	-7.40%	—
Current Drawdown Current decline from peak	-0.19%	0.00%	-0.19%
Average Drawdown Average peak-to-trough decline	-1.37%	-0.21%	-1.16%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.39%	0.07%	+0.32%

Volatility

CDSRX vs. CULAX - Volatility Comparison

Calvert Short Duration Income Fund Class R6 (CDSRX) has a higher volatility of 0.67% compared to Calvert Ultra-Short Duration Income Fund (CULAX) at 0.31%. This indicates that CDSRX's price experiences larger fluctuations and is considered to be riskier than CULAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	CDSRX	CULAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.67%	0.31%	+0.36%
Volatility (6M) Calculated over the trailing 6-month period	1.54%	0.84%	+0.70%
Volatility (1Y) Calculated over the trailing 1-year period	2.10%	1.32%	+0.78%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	2.42%	1.35%	+1.07%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	2.66%	1.42%	+1.24%

CDSRX vs. CULAX - Expense Ratio Comparison

CDSRX has a 0.45% expense ratio, which is lower than CULAX's 0.72% expense ratio.

Dividends

CDSRX vs. CULAX - Dividend Comparison

CDSRX's dividend yield for the trailing twelve months is around 4.67%, more than CULAX's 3.91% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
CDSRX Calvert Short Duration Income Fund Class R6	4.67%	4.55%	4.98%	3.52%	2.21%	2.56%	2.88%	2.75%	0.00%	0.00%	0.00%	0.00%
CULAX Calvert Ultra-Short Duration Income Fund	3.91%	4.13%	4.90%	4.52%	1.47%	0.64%	1.25%	2.44%	2.10%	1.13%	1.10%	0.66%

Frequently Asked Questions

Can I hold both CDSRX and CULAX in my portfolio?

CDSRX and CULAX have a correlation of 0.50, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, CDSRX or CULAX?

CDSRX has higher volatility (0.67%) compared to CULAX (0.31%). In terms of maximum drawdown, CDSRX dropped -9.96% vs CULAX's -7.40%.

Which has better risk-adjusted returns?

CULAX currently has the higher Sharpe Ratio (3.22 vs 2.30), 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.