BUYW vs. COSW

Last updated Apr 1, 2026

Compare and contrast key facts about Main Buywrite ETF (BUYW) and Roundhill COST WeeklyPay ETF (COSW).

BUYW and COSW are both exchange-traded funds (ETFs), meaning they are traded on stock exchanges and can be bought and sold throughout the day. BUYW is an actively managed fund by Main Funds. It was launched on Dec 29, 2015. COSW is an actively managed fund by Roundhill. It was launched on Oct 23, 2025.

Performance

BUYW vs. COSW - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Main Buywrite ETF (BUYW) and Roundhill COST WeeklyPay ETF (COSW). The values are adjusted to include any dividend payments, if applicable.

BUYW vs. COSW - Yearly Performance Comparison

	2026 (YTD)	2025
BUYW Main Buywrite ETF	-0.19%	1.87%
COSW Roundhill COST WeeklyPay ETF	17.20%	-10.71%

Returns By Period

In the year-to-date period, BUYW achieves a -0.19% return, which is significantly lower than COSW's 17.20% return.

BUYW

• 1D: 1.51%
• 1M: -0.91%
• YTD: -0.19%
• 6M: 2.11%
• 1Y: 8.89%
• 3Y*: 8.39%
• 5Y*: —
• 10Y*: —

COSW

• 1D: -0.54%
• 1M: -2.62%
• YTD: 17.20%
• 6M: —
• 1Y: —
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

BUYW vs. COSW - Expense Ratio Comparison

BUYW has a 1.29% expense ratio, which is higher than COSW's 0.99% expense ratio.

BUYW

Main Buywrite ETF

COSW

Roundhill COST WeeklyPay ETF

Return for Risk

BUYW vs. COSW — Risk / Return Rank

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

BUYW

BUYW Risk / Return Rank: 56
BUYW Sharpe Ratio Rank: 45
BUYW Sortino Ratio Rank: 50
BUYW Omega Ratio Rank: 68
BUYW Calmar Ratio Rank: 44
BUYW Martin Ratio Rank: 73

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.

BUYW vs. COSW - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Main Buywrite ETF (BUYW) and Roundhill COST WeeklyPay ETF (COSW). 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.

	BUYW	COSW	Difference
Sharpe ratio Return per unit of total volatility	0.80	—	—
Sortino ratio Return per unit of downside risk	1.32	—	—
Omega ratio Gain probability vs. loss probability	1.25	—	—
Calmar ratio Return relative to maximum drawdown	1.12	—	—
Martin ratio Return relative to average drawdown	7.48	—	—
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

Sharpe Ratios by Period

	BUYW	COSW	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.80	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	1.08	0.44	+0.64

Correlation

The correlation between BUYW and COSW is -0.07. This indicates that the assets' prices tend to move in opposite directions. Negative correlation can be particularly beneficial for diversification and risk management, as one asset may offset the losses of the other during market fluctuations.

Dividends

BUYW vs. COSW - Dividend Comparison

BUYW's dividend yield for the trailing twelve months is around 6.01%, less than COSW's 12.26% yield.

	TTM	2025	2024	2023	2022
BUYW Main Buywrite ETF	6.01%	5.89%	5.93%	5.95%	0.50%
COSW Roundhill COST WeeklyPay ETF	12.26%	4.96%	0.00%	0.00%	0.00%

Drawdowns

BUYW vs. COSW - Drawdown Comparison

The maximum BUYW drawdown since its inception was -9.36%, smaller than the maximum COSW drawdown of -12.17%. Use the drawdown chart below to compare losses from any high point for BUYW and COSW.

Drawdown Indicators

	BUYW	COSW	Difference
Max Drawdown Largest peak-to-trough decline	-9.36%	-12.17%	+2.81%
Max Drawdown (1Y) Largest decline over 1 year	-8.18%	—	—
Current Drawdown Current decline from peak	-1.11%	-3.28%	+2.17%
Average Drawdown Average peak-to-trough decline	-0.63%	-4.05%	+3.42%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.22%	—	—

Volatility

Volatility by Period

	BUYW	COSW	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.59%	—	—
Volatility (6M) Calculated over the trailing 6-month period	3.89%	—	—
Volatility (1Y) Calculated over the trailing 1-year period	11.09%	25.36%	-14.27%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	8.62%	25.36%	-16.74%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	8.62%	25.36%	-16.74%