CSTIX vs. FUMBX

Last updated Jun 23, 2026

CSTIX (Calamos Short-Term Bond Fund) and FUMBX (Fidelity Short-Term Treasury Bond Index Fund) are both Short-Term Bond funds. Over the past 5 years, CSTIX returned 2.53%/yr vs 1.33%/yr for FUMBX. A 0.78 correlation means they provide meaningful diversification when combined. CSTIX charges 0.40%/yr vs 0.03%/yr for FUMBX.

Performance

CSTIX vs. FUMBX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Calamos Short-Term Bond Fund (CSTIX) and Fidelity Short-Term Treasury Bond Index Fund (FUMBX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, CSTIX achieves a 0.24% return, which is significantly higher than FUMBX's -0.01% return.

CSTIX

• 1D: 0.00%
• 1M: 0.27%
• YTD: 0.24%
• 6M: 0.62%
• 1Y: 3.72%
• 3Y*: 4.88%
• 5Y*: 2.53%
• 10Y*: —

FUMBX

• 1D: 0.10%
• 1M: 0.26%
• YTD: -0.01%
• 6M: 0.34%
• 1Y: 2.99%
• 3Y*: 4.07%
• 5Y*: 1.33%
• 10Y*: —

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

CSTIX vs. FUMBX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018
CSTIX Calamos Short-Term Bond Fund	0.24%	6.11%	4.91%	4.76%	-3.04%	0.13%	4.06%	4.84%	0.62%
FUMBX Fidelity Short-Term Treasury Bond Index Fund	-0.01%	5.83%	3.25%	4.47%	-5.84%	-1.38%	4.22%	4.19%	1.91%

Correlation

The correlation between CSTIX and FUMBX is 0.83, 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	0.83
Correlation (3Y) Calculated over the trailing 3-year period	0.84
Correlation (5Y) Calculated over the trailing 5-year period	0.84
Correlation (All Time) Calculated using the full available price history since Sep 20, 2018	0.78

The correlation between CSTIX and FUMBX has been stable across timeframes, ranging from 0.78 to 0.84 - a consistent structural relationship.

Return for Risk

CSTIX vs. FUMBX — Risk / Return Rank

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

CSTIX

CSTIX Risk / Return Rank: 63
CSTIX Sharpe Ratio Rank: 47
CSTIX Sortino Ratio Rank: 78
CSTIX Omega Ratio Rank: 73
CSTIX Calmar Ratio Rank: 57
CSTIX Martin Ratio Rank: 58

FUMBX

FUMBX Risk / Return Rank: 33
FUMBX Sharpe Ratio Rank: 31
FUMBX Sortino Ratio Rank: 37
FUMBX Omega Ratio Rank: 37
FUMBX Calmar Ratio Rank: 32
FUMBX Martin Ratio Rank: 27

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.

CSTIX vs. FUMBX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Calamos Short-Term Bond Fund (CSTIX) and Fidelity Short-Term Treasury Bond Index Fund (FUMBX). 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.

	CSTIX	FUMBX	Difference
Sharpe ratio: Return per unit of total volatility	1.86	1.49	+0.37
Sortino ratio: Return per unit of downside risk	3.41	2.35	+1.06
Omega ratio: Gain probability vs. loss probability	1.43	1.30	+0.13
Calmar ratio: Return relative to maximum drawdown	2.77	2.02	+0.75
Martin ratio: Return relative to average drawdown	10.92	5.99	+4.93

CSTIX vs. FUMBX - Sharpe Ratio Comparison

The current CSTIX Sharpe Ratio is 1.86, which is comparable to the FUMBX Sharpe Ratio of 1.49. The chart below compares the historical Sharpe Ratios of CSTIX and FUMBX, 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

CSTIX vs. FUMBX - Drawdown Comparison

The maximum CSTIX drawdown since its inception was -6.03%, smaller than the maximum FUMBX drawdown of -8.83%. Use the drawdown chart below to compare losses from any high point for CSTIX and FUMBX.

Drawdown Indicators

	CSTIX	FUMBX	Difference
Max Drawdown Largest peak-to-trough decline	-6.03%	-8.83%	+2.80%
Max Drawdown (1Y) Largest decline over 1 year	-1.35%	-1.54%	+0.19%
Max Drawdown (3Y) Largest decline over 3 years	-1.35%	-1.57%	+0.22%
Max Drawdown (5Y) Largest decline over 5 years	-6.03%	-8.60%	+2.57%
Current Drawdown Current decline from peak	-0.34%	-0.96%	+0.62%
Average Drawdown Average peak-to-trough decline	-0.89%	-1.85%	+0.96%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.34%	0.52%	-0.18%

Volatility

CSTIX vs. FUMBX - Volatility Comparison

The current volatility for Calamos Short-Term Bond Fund (CSTIX) is 0.66%, while Fidelity Short-Term Treasury Bond Index Fund (FUMBX) has a volatility of 0.72%. This indicates that CSTIX experiences smaller price fluctuations and is considered to be less risky than FUMBX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	CSTIX	FUMBX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.66%	0.72%	-0.06%
Volatility (6M) Calculated over the trailing 6-month period	1.42%	1.56%	-0.14%
Volatility (1Y) Calculated over the trailing 1-year period	2.01%	2.08%	-0.07%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	2.28%	2.92%	-0.64%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	2.13%	2.49%	-0.36%

CSTIX vs. FUMBX - Expense Ratio Comparison

CSTIX has a 0.40% expense ratio, which is higher than FUMBX's 0.03% expense ratio.

Dividends

CSTIX vs. FUMBX - Dividend Comparison

CSTIX's dividend yield for the trailing twelve months is around 4.20%, more than FUMBX's 3.77% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017
CSTIX Calamos Short-Term Bond Fund	4.20%	4.55%	4.46%	3.02%	2.56%	3.37%	3.38%	3.43%	0.72%	0.00%
FUMBX Fidelity Short-Term Treasury Bond Index Fund	3.77%	3.51%	2.91%	1.64%	0.86%	1.15%	1.41%	1.88%	1.64%	0.34%

Frequently Asked Questions

Can I hold both CSTIX and FUMBX in my portfolio?

CSTIX and FUMBX have a correlation of 0.83, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, CSTIX or FUMBX?

FUMBX has higher volatility (0.72%) compared to CSTIX (0.66%). In terms of maximum drawdown, CSTIX dropped -6.03% vs FUMBX's -8.83%.

Which has better risk-adjusted returns?

CSTIX currently has the higher Sharpe Ratio (1.86 vs 1.49), 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.