CULAX vs. PTSHX

Last updated Jun 4, 2026

CULAX (Calvert Ultra-Short Duration Income Fund) and PTSHX (PIMCO Short Term Fund) are both Ultrashort Bond funds. Over the past 10 years, CULAX returned 2.47%/yr vs 2.98%/yr for PTSHX. At a 0.14 correlation, their price movements are largely independent. CULAX charges 0.72%/yr vs 0.45%/yr for PTSHX.

Performance

CULAX vs. PTSHX - Performance Comparison

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

Returns By Period

In the year-to-date period, CULAX achieves a 1.34% return, which is significantly lower than PTSHX's 1.92% return. Over the past 10 years, CULAX has underperformed PTSHX with an annualized return of 2.47%, while PTSHX has yielded a comparatively higher 2.98% annualized return.

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%

PTSHX

• 1D: 0.00%
• 1M: 0.46%
• YTD: 1.92%
• 6M: 2.31%
• 1Y: 4.87%
• 3Y*: 5.72%
• 5Y*: 3.65%
• 10Y*: 2.98%

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

CULAX vs. PTSHX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
CULAX Calvert Ultra-Short Duration Income Fund	1.34%	4.55%	5.69%	6.07%	-0.56%	0.43%	0.66%	3.30%	1.15%	1.27%
PTSHX PIMCO Short Term Fund	1.92%	4.88%	6.43%	6.09%	-0.55%	0.02%	2.75%	2.74%	1.51%	2.43%

Correlation

The correlation between CULAX and PTSHX is 0.33, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.33
Correlation (3Y) Calculated over the trailing 3-year period	0.14
Correlation (5Y) Calculated over the trailing 5-year period	0.18
Correlation (10Y) Calculated over the trailing 10-year period	0.17
Correlation (All Time) Calculated using the full available price history since Nov 1, 2006	0.14

The correlation between CULAX and PTSHX shifts across timeframes, from 0.14 (all time) to 0.33 (1 year), reflecting how their relationship changes across market environments.

Return for Risk

CULAX vs. PTSHX — Risk / Return Rank

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

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

PTSHX

PTSHX Risk / Return Rank: 99
PTSHX Sharpe Ratio Rank: 95
PTSHX Sortino Ratio Rank: 100
PTSHX Omega Ratio Rank: 99
PTSHX Calmar Ratio Rank: 100
PTSHX Martin Ratio Rank: 100

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.

CULAX vs. PTSHX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Calvert Ultra-Short Duration Income Fund (CULAX) and PIMCO Short Term Fund (PTSHX). 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.

	CULAX	PTSHX	Difference
Sharpe ratio: Return per unit of total volatility	3.22	3.42	-0.19
Sortino ratio: Return per unit of downside risk	11.38	11.59	-0.21
Omega ratio: Gain probability vs. loss probability	4.15	3.89	+0.27
Calmar ratio: Return relative to maximum drawdown	13.98	23.80	-9.82
Martin ratio: Return relative to average drawdown	56.95	77.59	-20.63
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

CULAX vs. PTSHX - Sharpe Ratio Comparison

The current CULAX Sharpe Ratio is 3.22, which is comparable to the PTSHX Sharpe Ratio of 3.42. The chart below compares the historical Sharpe Ratios of CULAX and PTSHX, 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

	CULAX	PTSHX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	3.22	3.42	-0.19
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	2.53	2.62	-0.09
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	1.75	2.22	-0.47
Sharpe Ratio (All Time) Calculated using the full available price history	2.07	1.71	+0.37

Drawdowns

CULAX vs. PTSHX - Drawdown Comparison

The maximum CULAX drawdown since its inception was -7.40%, which is greater than PTSHX's maximum drawdown of -5.12%. Use the drawdown chart below to compare losses from any high point for CULAX and PTSHX.

Drawdown Indicators

	CULAX	PTSHX	Difference
Max Drawdown Largest peak-to-trough decline	-7.40%	-5.12%	-2.28%
Max Drawdown (1Y) Largest decline over 1 year	-0.30%	-0.21%	-0.09%
Max Drawdown (3Y) Largest decline over 3 years	-0.30%	-0.41%	+0.11%
Max Drawdown (5Y) Largest decline over 5 years	-2.19%	-2.33%	+0.14%
Max Drawdown (10Y) Largest decline over 10 years	-7.40%	-4.79%	-2.61%
Current Drawdown Current decline from peak	0.00%	-0.10%	+0.10%
Average Drawdown Average peak-to-trough decline	-0.21%	-0.19%	-0.02%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.07%	0.06%	+0.01%

Volatility

CULAX vs. PTSHX - Volatility Comparison

The current volatility for Calvert Ultra-Short Duration Income Fund (CULAX) is 0.31%, while PIMCO Short Term Fund (PTSHX) has a volatility of 0.39%. This indicates that CULAX experiences smaller price fluctuations and is considered to be less risky than PTSHX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	CULAX	PTSHX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.31%	0.39%	-0.08%
Volatility (6M) Calculated over the trailing 6-month period	0.84%	1.02%	-0.18%
Volatility (1Y) Calculated over the trailing 1-year period	1.32%	1.44%	-0.12%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	1.35%	1.40%	-0.05%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	1.42%	1.35%	+0.07%

CULAX vs. PTSHX - Expense Ratio Comparison

CULAX has a 0.72% expense ratio, which is higher than PTSHX's 0.45% expense ratio.

Dividends

CULAX vs. PTSHX - Dividend Comparison

CULAX's dividend yield for the trailing twelve months is around 3.91%, less than PTSHX's 4.43% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
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%
PTSHX PIMCO Short Term Fund	4.43%	4.75%	5.16%	4.51%	2.80%	0.63%	1.78%	2.92%	2.65%	1.69%	1.67%	1.57%

Frequently Asked Questions

Can I hold both CULAX and PTSHX in my portfolio?

CULAX and PTSHX have a correlation of 0.33, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, CULAX or PTSHX?

PTSHX has higher volatility (0.39%) compared to CULAX (0.31%). In terms of maximum drawdown, CULAX dropped -7.40% vs PTSHX's -5.12%.

Which has better risk-adjusted returns?

PTSHX currently has the higher Sharpe Ratio (3.42 vs 3.22), 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.