WEEK vs. BILS

Last updated Jun 24, 2026

WEEK (Roundhill Weekly T-Bill ETF) and BILS (SPDR Bloomberg 3-12 Month T-Bill ETF) are both Ultrashort Bond funds. WEEK is actively managed, while BILS is passively managed. Over the past year, WEEK returned 3.72% vs 3.84% for BILS. At a 0.34 correlation, their price movements are largely independent. WEEK charges 0.19%/yr vs 0.14%/yr for BILS.

Performance

WEEK vs. BILS - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Roundhill Weekly T-Bill ETF (WEEK) and SPDR Bloomberg 3-12 Month T-Bill ETF (BILS). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

The year-to-date returns for both investments are quite close, with WEEK having a 1.56% return and BILS slightly higher at 1.57%.

WEEK

• 1D: -0.09%
• 1M: 0.24%
• YTD: 1.56%
• 6M: 1.70%
• 1Y: 3.72%
• 3Y*: —
• 5Y*: —
• 10Y*: —

BILS

• 1D: 0.00%
• 1M: 0.24%
• YTD: 1.57%
• 6M: 1.66%
• 1Y: 3.84%
• 3Y*: 4.61%
• 5Y*: 3.33%
• 10Y*: —

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

WEEK vs. BILS - Yearly Performance Comparison

	2026 (YTD)	2025
WEEK Roundhill Weekly T-Bill ETF	1.56%	3.37%
BILS SPDR Bloomberg 3-12 Month T-Bill ETF	1.57%	3.46%

Correlation

The correlation between WEEK and BILS 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 (All Time) Calculated using the full available price history since Mar 6, 2025	0.34

Return for Risk

WEEK vs. BILS — Risk / Return Rank

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

WEEK

WEEK Risk / Return Rank: 99
WEEK Sharpe Ratio Rank: 99
WEEK Sortino Ratio Rank: 99
WEEK Omega Ratio Rank: 99
WEEK Calmar Ratio Rank: 99
WEEK Martin Ratio Rank: 99

BILS

BILS Risk / Return Rank: 100
BILS Sharpe Ratio Rank: 100
BILS Sortino Ratio Rank: 100
BILS Omega Ratio Rank: 100
BILS Calmar Ratio Rank: 100
BILS 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.

WEEK vs. BILS - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Roundhill Weekly T-Bill ETF (WEEK) and SPDR Bloomberg 3-12 Month T-Bill ETF (BILS). 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.

	WEEK	BILS	Difference
Sharpe ratio: Return per unit of total volatility	8.53	16.64	-8.11
Sortino ratio: Return per unit of downside risk	16.60	87.69	-71.09
Omega ratio: Gain probability vs. loss probability	4.07	34.24	-30.17
Calmar ratio: Return relative to maximum drawdown	28.78	127.82	-99.04
Martin ratio: Return relative to average drawdown	233.16	1,285.26	-1,052.10

WEEK vs. BILS - Sharpe Ratio Comparison

The current WEEK Sharpe Ratio is 8.53, which is lower than the BILS Sharpe Ratio of 16.64. The chart below compares the historical Sharpe Ratios of WEEK and BILS, 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

WEEK vs. BILS - Drawdown Comparison

The maximum WEEK drawdown since its inception was -0.13%, smaller than the maximum BILS drawdown of -0.41%. Use the drawdown chart below to compare losses from any high point for WEEK and BILS.

Drawdown Indicators

	WEEK	BILS	Difference
Max Drawdown Largest peak-to-trough decline	-0.13%	-0.41%	+0.28%
Max Drawdown (1Y) Largest decline over 1 year	-0.13%	-0.03%	-0.10%
Max Drawdown (3Y) Largest decline over 3 years	—	-0.04%	—
Max Drawdown (5Y) Largest decline over 5 years	—	-0.37%	—
Current Drawdown Current decline from peak	-0.09%	0.00%	-0.09%
Average Drawdown Average peak-to-trough decline	-0.01%	-0.04%	+0.03%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.02%	0.00%	+0.02%

Volatility

WEEK vs. BILS - Volatility Comparison

Roundhill Weekly T-Bill ETF (WEEK) has a higher volatility of 0.16% compared to SPDR Bloomberg 3-12 Month T-Bill ETF (BILS) at 0.06%. This indicates that WEEK's price experiences larger fluctuations and is considered to be riskier than BILS based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	WEEK	BILS	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.16%	0.06%	+0.10%
Volatility (6M) Calculated over the trailing 6-month period	0.29%	0.14%	+0.15%
Volatility (1Y) Calculated over the trailing 1-year period	0.44%	0.23%	+0.21%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	0.40%	0.31%	+0.09%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	0.40%	0.30%	+0.10%

WEEK vs. BILS - Expense Ratio Comparison

WEEK has a 0.19% expense ratio, which is higher than BILS's 0.14% 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

WEEK vs. BILS - Dividend Comparison

WEEK's dividend yield for the trailing twelve months is around 3.70%, less than BILS's 3.81% yield.

Position	TTM	2025	2024	2023	2022
BILS SPDR Bloomberg 3-12 Month T-Bill ETF	3.81%	4.08%	5.01%	4.98%	1.61%
WEEK Roundhill Weekly T-Bill ETF	3.70%	3.27%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both WEEK and BILS in my portfolio?

WEEK and BILS 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, WEEK or BILS?

WEEK has higher volatility (0.16%) compared to BILS (0.06%). In terms of maximum drawdown, WEEK dropped -0.13% vs BILS's -0.41%.

Which ETF is better, WEEK or BILS?

On 1-year performance, BILS leads with 3.84% vs 3.72% for WEEK. On fees, BILS is cheaper at 0.14% per year. On volatility, BILS has been the lower-risk option at 0.06%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, WEEK or BILS?

Over the 1-year period, BILS has performed better with a 3.84% return vs 3.72%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, WEEK or BILS?

BILS is cheaper with a 0.14% expense ratio, compared with 0.19% for WEEK.

Which ETF pays a higher dividend yield, WEEK or BILS?

BILS has the higher dividend yield at 3.81%, compared with 3.70% for WEEK.

What is the main difference between WEEK and BILS?

They also come from different issuers: Roundhill and State Street. Their fees differ too: 0.19% for WEEK and 0.14% for BILS.

Which has better risk-adjusted returns?

BILS currently has the higher Sharpe Ratio (16.64 vs 8.53), 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.