WEEK vs. SPY

Last updated Jun 23, 2026

WEEK (Roundhill Weekly T-Bill ETF) and SPY (State Street SPDR S&P 500 ETF) are both exchange-traded funds - WEEK is a Ultrashort Bond fund actively managed by Roundhill, while SPY is a S&P 500 fund tracking the S&P 500 Index. WEEK is actively managed, while SPY is passively managed. Over the past year, WEEK returned 3.83% vs 26.65% for SPY. At a 0.05 correlation, their price movements are largely independent. WEEK charges 0.19%/yr vs 0.09%/yr for SPY.

Performance

WEEK vs. SPY - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Roundhill Weekly T-Bill ETF (WEEK) and State Street SPDR S&P 500 ETF (SPY). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, WEEK achieves a 1.65% return, which is significantly lower than SPY's 9.74% return.

WEEK

• 1D: 0.01%
• 1M: 0.33%
• YTD: 1.65%
• 6M: 1.77%
• 1Y: 3.83%
• 3Y*: —
• 5Y*: —
• 10Y*: —

SPY

• 1D: -0.31%
• 1M: 0.09%
• YTD: 9.74%
• 6M: 9.27%
• 1Y: 26.65%
• 3Y*: 21.27%
• 5Y*: 13.51%
• 10Y*: 15.70%

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

WEEK vs. SPY - Yearly Performance Comparison

	2026 (YTD)	2025
WEEK Roundhill Weekly T-Bill ETF	1.65%	3.37%
SPY State Street SPDR S&P 500 ETF	9.74%	18.33%

Correlation

The correlation between WEEK and SPY 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 (All Time) Calculated using the full available price history since Mar 6, 2025	0.05

Return for Risk

WEEK vs. SPY — 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

SPY

SPY Risk / Return Rank: 68
SPY Sharpe Ratio Rank: 69
SPY Sortino Ratio Rank: 66
SPY Omega Ratio Rank: 68
SPY Calmar Ratio Rank: 63
SPY Martin Ratio Rank: 74

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. SPY - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Roundhill Weekly T-Bill ETF (WEEK) and State Street SPDR S&P 500 ETF (SPY). 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	SPY	Difference
Sharpe ratio: Return per unit of total volatility	9.04	2.16	+6.89
Sortino ratio: Return per unit of downside risk	18.70	2.91	+15.79
Omega ratio: Gain probability vs. loss probability	4.42	1.39	+3.02
Calmar ratio: Return relative to maximum drawdown	29.62	3.01	+26.61
Martin ratio: Return relative to average drawdown	256.61	13.54	+243.08

WEEK vs. SPY - Sharpe Ratio Comparison

The current WEEK Sharpe Ratio is 9.04, which is higher than the SPY Sharpe Ratio of 2.16. The chart below compares the historical Sharpe Ratios of WEEK and SPY, 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. SPY - Drawdown Comparison

The maximum WEEK drawdown since its inception was -0.13%, smaller than the maximum SPY drawdown of -55.19%. Use the drawdown chart below to compare losses from any high point for WEEK and SPY.

Drawdown Indicators

	WEEK	SPY	Difference
Max Drawdown Largest peak-to-trough decline	-0.13%	-55.19%	+55.06%
Max Drawdown (1Y) Largest decline over 1 year	-0.13%	-8.88%	+8.75%
Max Drawdown (3Y) Largest decline over 3 years	—	-18.76%	—
Max Drawdown (5Y) Largest decline over 5 years	—	-24.50%	—
Max Drawdown (10Y) Largest decline over 10 years	—	-33.72%	—
Current Drawdown Current decline from peak	0.00%	-1.75%	+1.75%
Average Drawdown Average peak-to-trough decline	-0.01%	-9.04%	+9.03%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.01%	1.97%	-1.96%

Volatility

WEEK vs. SPY - Volatility Comparison

The current volatility for Roundhill Weekly T-Bill ETF (WEEK) is 0.13%, while State Street SPDR S&P 500 ETF (SPY) has a volatility of 4.64%. This indicates that WEEK experiences smaller price fluctuations and is considered to be less risky than SPY based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	WEEK	SPY	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.13%	4.64%	-4.51%
Volatility (6M) Calculated over the trailing 6-month period	0.27%	9.75%	-9.48%
Volatility (1Y) Calculated over the trailing 1-year period	0.43%	12.43%	-12.00%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	0.39%	17.14%	-16.75%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	0.39%	17.99%	-17.60%

WEEK vs. SPY - Expense Ratio Comparison

WEEK has a 0.19% expense ratio, which is higher than SPY's 0.09% 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. SPY - Dividend Comparison

WEEK's dividend yield for the trailing twelve months is around 3.70%, more than SPY's 1.01% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
SPY State Street SPDR S&P 500 ETF	1.01%	1.07%	1.21%	1.40%	1.65%	1.20%	1.52%	1.75%	2.04%	1.80%	2.03%	2.06%
WEEK Roundhill Weekly T-Bill ETF	3.70%	3.27%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both WEEK and SPY in my portfolio?

WEEK and SPY 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, WEEK or SPY?

SPY has higher volatility (4.64%) compared to WEEK (0.13%). In terms of maximum drawdown, WEEK dropped -0.13% vs SPY's -55.19%.

Which ETF is better, WEEK or SPY?

On 1-year performance, SPY leads with 26.65% vs 3.83% for WEEK. On fees, SPY is cheaper at 0.09% per year. On volatility, WEEK has been the lower-risk option at 0.13%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, WEEK or SPY?

Over the 1-year period, SPY has performed better with a 26.65% return vs 3.83%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, WEEK or SPY?

SPY is cheaper with a 0.09% expense ratio, compared with 0.19% for WEEK.

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

WEEK has the higher dividend yield at 3.70%, compared with 1.01% for SPY.

What is the main difference between WEEK and SPY?

WEEK is categorized as Ultrashort Bond, while SPY is S&P 500. They also come from different issuers: Roundhill and State Street. Their fees differ too: 0.19% for WEEK and 0.09% for SPY.

Which has better risk-adjusted returns?

WEEK currently has the higher Sharpe Ratio (9.04 vs 2.16), 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.