TBUX vs. VMRXX

Last updated Jun 9, 2026

TBUX (T. Rowe Price Ultra Short-Term Bond ETF) and VMRXX (Vanguard Cash Reserves Federal Money Market Fund Admiral Shares) are both funds - TBUX is a Ultrashort Bond fund actively managed by T. Rowe Price, while VMRXX is a Money Market fund actively managed by Vanguard. Both are actively managed. Over the past 3 years, TBUX returned 5.85%/yr vs 3.96%/yr for VMRXX. At a 0.02 correlation, their price movements are largely independent. TBUX charges 0.17%/yr vs 0.10%/yr for VMRXX.

Performance

TBUX vs. VMRXX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in T. Rowe Price Ultra Short-Term Bond ETF (TBUX) and Vanguard Cash Reserves Federal Money Market Fund Admiral Shares (VMRXX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, TBUX achieves a 1.69% return, which is significantly higher than VMRXX's 1.50% return.

TBUX

• 1D: 0.06%
• 1M: 0.29%
• YTD: 1.69%
• 6M: 2.08%
• 1Y: 4.88%
• 3Y*: 5.85%
• 5Y*: —
• 10Y*: —

VMRXX

• 1D: 0.00%
• 1M: 0.30%
• YTD: 1.50%
• 6M: 1.83%
• 1Y: 3.96%
• 3Y*: 3.96%
• 5Y*: 2.76%
• 10Y*: —

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

TBUX vs. VMRXX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021
TBUX T. Rowe Price Ultra Short-Term Bond ETF	1.69%	5.37%	6.38%	6.39%	-0.13%	-0.22%
VMRXX Vanguard Cash Reserves Federal Money Market Fund Admiral Shares	1.50%	4.25%	3.45%	4.65%	0.00%	0.01%

Correlation

The correlation between TBUX and VMRXX is 0.05, meaning there is essentially no relationship between their price movements. Each responds to its own set of market drivers, making them strong candidates for combining in a diversified portfolio.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.05
Correlation (3Y) Calculated over the trailing 3-year period	-0.01
Correlation (All Time) Calculated using the full available price history since Sep 30, 2021	0.02

TBUX vs. VMRXX - Sectors Allocation Comparison

Sectors	TBUX	VMRXX
Technology	52.7%	-
Communication Services	15.2%	-
Consumer Cyclical	14.3%	-
Consumer Defensive	5.5%	-
Healthcare	5.0%	-
Industrials	3.5%	-
Basic Materials	1.3%	-
Utilities	1.2%	-
Energy	0.6%	-
Financial Services	0.5%	17.8%
Real Estate	0.2%	-

Return for Risk

TBUX vs. VMRXX — Risk / Return Rank

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

TBUX

TBUX Risk / Return Rank: 99
TBUX Sharpe Ratio Rank: 99
TBUX Sortino Ratio Rank: 99
TBUX Omega Ratio Rank: 99
TBUX Calmar Ratio Rank: 99
TBUX 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.

TBUX vs. VMRXX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for T. Rowe Price Ultra Short-Term Bond ETF (TBUX) and Vanguard Cash Reserves Federal Money Market Fund Admiral Shares (VMRXX). 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.

	TBUX	VMRXX	Difference
Sharpe ratio: Return per unit of total volatility	7.27	3.67	+3.60
Sortino ratio: Return per unit of downside risk	14.70	—	—
Omega ratio: Gain probability vs. loss probability	3.15	—	—
Calmar ratio: Return relative to maximum drawdown	48.80	—	—
Martin ratio: Return relative to average drawdown	185.24	—	—
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

TBUX vs. VMRXX - Sharpe Ratio Comparison

The current TBUX Sharpe Ratio is 7.27, which is higher than the VMRXX Sharpe Ratio of 3.67. The chart below compares the historical Sharpe Ratios of TBUX and VMRXX, 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

	TBUX	VMRXX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	7.27	3.67	+3.60
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	—	2.77	—
Sharpe Ratio (All Time) Calculated using the full available price history	3.88	2.76	+1.12

Drawdowns

TBUX vs. VMRXX - Drawdown Comparison

The maximum TBUX drawdown since its inception was -1.79%, which is greater than VMRXX's maximum drawdown of 0.00%. Use the drawdown chart below to compare losses from any high point for TBUX and VMRXX.

Drawdown Indicators

	TBUX	VMRXX	Difference
Max Drawdown Largest peak-to-trough decline	-1.79%	0.00%	-1.79%
Max Drawdown (1Y) Largest decline over 1 year	-0.10%	0.00%	-0.10%
Max Drawdown (3Y) Largest decline over 3 years	-0.33%	0.00%	-0.33%
Max Drawdown (5Y) Largest decline over 5 years	—	0.00%	—
Current Drawdown Current decline from peak	-0.04%	0.00%	-0.04%
Average Drawdown Average peak-to-trough decline	-0.28%	0.00%	-0.28%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.03%	0.00%	+0.03%

Volatility

TBUX vs. VMRXX - Volatility Comparison

The current volatility for T. Rowe Price Ultra Short-Term Bond ETF (TBUX) is 0.22%, while Vanguard Cash Reserves Federal Money Market Fund Admiral Shares (VMRXX) has a volatility of 0.30%. This indicates that TBUX experiences smaller price fluctuations and is considered to be less risky than VMRXX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	TBUX	VMRXX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.22%	0.30%	-0.08%
Volatility (6M) Calculated over the trailing 6-month period	0.46%	0.79%	-0.33%
Volatility (1Y) Calculated over the trailing 1-year period	0.67%	1.12%	-0.45%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	1.07%	1.02%	+0.05%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	1.07%	1.02%	+0.05%

TBUX vs. VMRXX - Expense Ratio Comparison

TBUX has a 0.17% expense ratio, which is higher than VMRXX's 0.10% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

TBUX vs. VMRXX - Dividend Comparison

TBUX's dividend yield for the trailing twelve months is around 4.48%, more than VMRXX's 3.88% yield.

Position	TTM	2025	2024	2023	2022	2021
TBUX T. Rowe Price Ultra Short-Term Bond ETF	4.48%	4.67%	5.39%	4.66%	2.58%	0.27%
VMRXX Vanguard Cash Reserves Federal Money Market Fund Admiral Shares	3.88%	4.15%	3.38%	4.54%	0.00%	0.01%

Frequently Asked Questions

Can I hold both TBUX and VMRXX in my portfolio?

TBUX and VMRXX have a correlation of 0.05, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, TBUX or VMRXX?

VMRXX has higher volatility (0.30%) compared to TBUX (0.22%). In terms of maximum drawdown, TBUX dropped -1.79% vs VMRXX's 0.00%.

Which has better risk-adjusted returns?

TBUX currently has the higher Sharpe Ratio (7.27 vs 3.67), 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.