VCPIX vs. STMGX

Last updated Jun 3, 2026

VCPIX (Vanguard Core-Plus Bond Fund Investor Shares) and STMGX (American Beacon Stephens Mid-Cap Growth Fund) are both mutual funds - VCPIX is a Total Bond Market fund managed by Vanguard, while STMGX is a Mid Cap Growth Equities fund managed by American Beacon. Over the past 3 years, VCPIX returned 5.30%/yr vs 16.97%/yr for STMGX. At a 0.23 correlation, their price movements are largely independent. VCPIX charges 0.30%/yr vs 1.14%/yr for STMGX.

Performance

VCPIX vs. STMGX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Core-Plus Bond Fund Investor Shares (VCPIX) and American Beacon Stephens Mid-Cap Growth Fund (STMGX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, VCPIX achieves a 0.62% return, which is significantly lower than STMGX's 10.87% return.

VCPIX

• 1D: -0.07%
• 1M: 0.16%
• YTD: 0.62%
• 6M: 0.79%
• 1Y: 6.04%
• 3Y*: 5.30%
• 5Y*: —
• 10Y*: —

STMGX

• 1D: 1.29%
• 1M: 7.67%
• YTD: 10.87%
• 6M: 10.56%
• 1Y: 21.93%
• 3Y*: 16.97%
• 5Y*: 6.99%
• 10Y*: 13.77%

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

VCPIX vs. STMGX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021
VCPIX Vanguard Core-Plus Bond Fund Investor Shares	0.62%	8.01%	2.83%	6.64%	-12.68%	0.35%
STMGX American Beacon Stephens Mid-Cap Growth Fund	10.87%	12.98%	13.16%	25.22%	-28.31%	1.63%

Correlation

The correlation between VCPIX and STMGX is 0.30, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.30
Correlation (3Y) Calculated over the trailing 3-year period	0.25
Correlation (All Time) Calculated using the full available price history since Oct 15, 2021	0.23

Return for Risk

VCPIX vs. STMGX — Risk / Return Rank

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

VCPIX

VCPIX Risk / Return Rank: 32
VCPIX Sharpe Ratio Rank: 31
VCPIX Sortino Ratio Rank: 33
VCPIX Omega Ratio Rank: 31
VCPIX Calmar Ratio Rank: 33
VCPIX Martin Ratio Rank: 30

STMGX

STMGX Risk / Return Rank: 26
STMGX Sharpe Ratio Rank: 23
STMGX Sortino Ratio Rank: 22
STMGX Omega Ratio Rank: 20
STMGX Calmar Ratio Rank: 31
STMGX Martin Ratio Rank: 32

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.

VCPIX vs. STMGX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Core-Plus Bond Fund Investor Shares (VCPIX) and American Beacon Stephens Mid-Cap Growth Fund (STMGX). 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.

	VCPIX	STMGX	Difference
Sharpe ratio Return per unit of total volatility	1.63	1.39	+0.24
Sortino ratio Return per unit of downside risk	2.42	2.00	+0.43
Omega ratio Gain probability vs. loss probability	1.30	1.24	+0.06
Calmar ratio Return relative to maximum drawdown	2.19	2.12	+0.07
Martin ratio Return relative to average drawdown	7.16	7.48	-0.33
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

VCPIX vs. STMGX - Sharpe Ratio Comparison

The current VCPIX Sharpe Ratio is 1.63, which is comparable to the STMGX Sharpe Ratio of 1.39. The chart below compares the historical Sharpe Ratios of VCPIX and STMGX, 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

	VCPIX	STMGX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.63	1.39	+0.24
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	—	0.34	—
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.66	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.17	0.46	-0.29

Drawdowns

VCPIX vs. STMGX - Drawdown Comparison

The maximum VCPIX drawdown since its inception was -17.33%, smaller than the maximum STMGX drawdown of -57.58%. Use the drawdown chart below to compare losses from any high point for VCPIX and STMGX.

Drawdown Indicators

	VCPIX	STMGX	Difference
Max Drawdown Largest peak-to-trough decline	-17.33%	-57.58%	+40.25%
Max Drawdown (1Y) Largest decline over 1 year	-2.72%	-10.84%	+8.12%
Max Drawdown (3Y) Largest decline over 3 years	-5.68%	-22.50%	+16.82%
Max Drawdown (5Y) Largest decline over 5 years	—	-36.59%	—
Max Drawdown (10Y) Largest decline over 10 years	—	-36.59%	—
Current Drawdown Current decline from peak	-1.12%	0.00%	-1.12%
Average Drawdown Average peak-to-trough decline	-6.60%	-10.16%	+3.56%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.83%	3.07%	-2.24%

Volatility

VCPIX vs. STMGX - Volatility Comparison

The current volatility for Vanguard Core-Plus Bond Fund Investor Shares (VCPIX) is 1.24%, while American Beacon Stephens Mid-Cap Growth Fund (STMGX) has a volatility of 4.24%. This indicates that VCPIX experiences smaller price fluctuations and is considered to be less risky than STMGX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VCPIX	STMGX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.24%	4.24%	-3.00%
Volatility (6M) Calculated over the trailing 6-month period	2.60%	12.70%	-10.10%
Volatility (1Y) Calculated over the trailing 1-year period	3.57%	16.29%	-12.72%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	5.69%	20.83%	-15.14%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.69%	20.89%	-15.20%

VCPIX vs. STMGX - Expense Ratio Comparison

VCPIX has a 0.30% expense ratio, which is lower than STMGX's 1.14% expense ratio.

Dividends

VCPIX vs. STMGX - Dividend Comparison

VCPIX's dividend yield for the trailing twelve months is around 4.74%, less than STMGX's 31.01% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
STMGX American Beacon Stephens Mid-Cap Growth Fund	31.01%	34.38%	4.86%	0.00%	3.42%	7.49%	1.45%	3.60%	9.39%	5.40%	6.65%	5.62%
VCPIX Vanguard Core-Plus Bond Fund Investor Shares	4.74%	4.76%	5.08%	4.46%	3.15%	0.25%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both VCPIX and STMGX in my portfolio?

VCPIX and STMGX have a correlation of 0.30, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, VCPIX or STMGX?

STMGX has higher volatility (4.24%) compared to VCPIX (1.24%). In terms of maximum drawdown, VCPIX dropped -17.33% vs STMGX's -57.58%.

Which has better risk-adjusted returns?

VCPIX currently has the higher Sharpe Ratio (1.63 vs 1.39), 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.