TMDIX vs. VMGMX

Last updated Jul 14, 2026

TMDIX (AMG TimesSquare Mid Cap Growth Fund) and VMGMX (Vanguard Mid-Cap Growth Index Fund Admiral Shares) are both Mid Cap Growth Equities funds. Over the past 10 years, TMDIX returned 13.15%/yr vs 11.89%/yr for VMGMX. With a 0.96 correlation, they move nearly in lockstep. TMDIX charges 0.98%/yr vs 0.07%/yr for VMGMX.

Performance

TMDIX vs. VMGMX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in AMG TimesSquare Mid Cap Growth Fund (TMDIX) and Vanguard Mid-Cap Growth Index Fund Admiral Shares (VMGMX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, TMDIX achieves a 7.57% return, which is significantly lower than VMGMX's 8.65% return. Over the past 10 years, TMDIX has outperformed VMGMX with an annualized return of 13.15%, while VMGMX has yielded a comparatively lower 11.89% annualized return.

TMDIX

• 1D: -0.88%
• 1M: 3.14%
• 6M: 4.09%
• YTD: 7.57%
• 1Y: -2.17%
• 3Y*: 8.14%
• 5Y*: 3.64%
• 10Y*: 13.15%

VMGMX

• 1D: -0.40%
• 1M: 1.84%
• 6M: 5.84%
• YTD: 8.65%
• 1Y: 7.29%
• 3Y*: 13.94%
• 5Y*: 5.55%
• 10Y*: 11.89%

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

TMDIX vs. VMGMX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
TMDIX AMG TimesSquare Mid Cap Growth Fund	7.57%	-1.76%	10.84%	25.07%	-22.26%	16.75%	33.42%	63.26%	-4.28%	22.66%
VMGMX Vanguard Mid-Cap Growth Index Fund Admiral Shares	8.65%	10.69%	15.65%	23.93%	-28.84%	20.48%	34.45%	33.85%	-5.61%	21.83%

Correlation

The correlation between TMDIX and VMGMX is 0.93, 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	0.93
Correlation (3Y) Calculated over the trailing 3-year period	0.93
Correlation (5Y) Calculated over the trailing 5-year period	0.95
Correlation (10Y) Calculated over the trailing 10-year period	0.96
Correlation (All Time) Calculated using the full available price history since Sep 27, 2011	0.96

The correlation between TMDIX and VMGMX has been stable across timeframes, ranging from 0.93 to 0.96 - a consistent structural relationship.

Return for Risk

TMDIX vs. VMGMX — Risk / Return Rank

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

TMDIX

TMDIX Risk / Return Rank: 3
TMDIX Sharpe Ratio Rank: 2
TMDIX Sortino Ratio Rank: 3
TMDIX Omega Ratio Rank: 3
TMDIX Calmar Ratio Rank: 3
TMDIX Martin Ratio Rank: 3

VMGMX

VMGMX Risk / Return Rank: 7
VMGMX Sharpe Ratio Rank: 7
VMGMX Sortino Ratio Rank: 7
VMGMX Omega Ratio Rank: 7
VMGMX Calmar Ratio Rank: 7
VMGMX Martin Ratio Rank: 7

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.

TMDIX vs. VMGMX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for AMG TimesSquare Mid Cap Growth Fund (TMDIX) and Vanguard Mid-Cap Growth Index Fund Admiral Shares (VMGMX). 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.

	TMDIX	VMGMX	Difference
Sharpe ratio: Return per unit of total volatility	-0.15	0.39	-0.54
Sortino ratio: Return per unit of downside risk	-0.07	0.66	-0.72
Omega ratio: Gain probability vs. loss probability	0.99	1.08	-0.09
Calmar ratio: Return relative to maximum drawdown	-0.12	0.42	-0.54
Martin ratio: Return relative to average drawdown	-0.25	1.24	-1.49

TMDIX vs. VMGMX - Sharpe Ratio Comparison

The current TMDIX Sharpe Ratio is -0.15, which is lower than the VMGMX Sharpe Ratio of 0.39. The chart below compares the historical Sharpe Ratios of TMDIX and VMGMX, 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

TMDIX vs. VMGMX - Drawdown Comparison

The maximum TMDIX drawdown since its inception was -48.73%, which is greater than VMGMX's maximum drawdown of -37.17%. Use the drawdown chart below to compare losses from any high point for TMDIX and VMGMX.

Drawdown Indicators

	TMDIX	VMGMX	Difference
Max Drawdown Largest peak-to-trough decline	-48.73%	-37.17%	-11.56%
Max Drawdown (1Y) Largest decline over 1 year	-25.45%	-15.95%	-9.50%
Max Drawdown (3Y) Largest decline over 3 years	-25.45%	-21.65%	-3.80%
Max Drawdown (5Y) Largest decline over 5 years	-30.53%	-37.17%	+6.64%
Max Drawdown (10Y) Largest decline over 10 years	-35.44%	-37.17%	+1.73%
Current Drawdown Current decline from peak	-9.93%	-1.37%	-8.56%
Average Drawdown Average peak-to-trough decline	-7.17%	-6.98%	-0.19%
Ulcer Index Depth and duration of drawdowns from previous peaks	12.64%	5.35%	+7.29%

Volatility

TMDIX vs. VMGMX - Volatility Comparison

The current volatility for AMG TimesSquare Mid Cap Growth Fund (TMDIX) is 5.94%, while Vanguard Mid-Cap Growth Index Fund Admiral Shares (VMGMX) has a volatility of 6.44%. This indicates that TMDIX experiences smaller price fluctuations and is considered to be less risky than VMGMX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	TMDIX	VMGMX	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.94%	6.44%	-0.50%
Volatility (6M) Calculated over the trailing 6-month period	13.76%	13.90%	-0.14%
Volatility (1Y) Calculated over the trailing 1-year period	20.41%	17.15%	+3.26%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	20.55%	21.62%	-1.07%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	21.08%	21.01%	+0.07%

TMDIX vs. VMGMX - Expense Ratio Comparison

TMDIX has a 0.98% expense ratio, which is higher than VMGMX's 0.07% expense ratio.

Dividends

TMDIX vs. VMGMX - Dividend Comparison

TMDIX has not paid dividends to shareholders, while VMGMX's dividend yield for the trailing twelve months is around 0.59%.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
TMDIX AMG TimesSquare Mid Cap Growth Fund	0.00%	0.00%	8.08%	3.98%	3.69%	29.72%	18.28%	31.06%	16.38%	14.44%	5.90%	7.73%
VMGMX Vanguard Mid-Cap Growth Index Fund Admiral Shares	0.59%	0.64%	0.67%	0.71%	0.78%	0.34%	0.56%	0.78%	0.84%	0.72%	0.81%	0.82%

Frequently Asked Questions

Can I hold both TMDIX and VMGMX in my portfolio?

With a correlation of 0.93, TMDIX and VMGMX move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, TMDIX or VMGMX?

VMGMX has higher volatility (6.44%) compared to TMDIX (5.94%). In terms of maximum drawdown, TMDIX dropped -48.73% vs VMGMX's -37.17%.

Which has better risk-adjusted returns?

VMGMX currently has the higher Sharpe Ratio (0.39 vs -0.15), 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.