Alpha Architect 1-3 Month Box ETF

Q: How does BOXX track Treasury returns without holding Treasuries?

BOXX uses an options strategy called a 'Box Spread'. It involves buying a bull call spread and a bear put spread with the same expiration dates on the S&P 500 (SPX). This combination creates a risk-free payoff at expiration. By executing this trade, BOXX is essentially lending cash to the options market at the 'implied risk-free rate', which perfectly tracks the yield of short-term Treasury bills.

Q: Why go through the trouble of using options?

Taxes. When you hold a Treasury bill ETF like SGOV, the yield is paid out as monthly dividends (ordinary income), which is taxed at your highest marginal rate. BOXX generates its return through the appreciation of its options contracts. When you sell BOXX, the profit is treated as a capital gain, which usually has a much lower tax rate.

Q: Is BOXX as safe as a Treasury bill?

Almost, but not exactly. Treasury bills are backed by the full faith and credit of the US Government. BOXX is backed by the Options Clearing Corporation (OCC). While the OCC is considered systemically important and incredibly safe, it is technically a step below direct US Government backing.

Q: What is the biggest risk for BOXX?

Regulatory/Tax risk. The main appeal of BOXX is its tax advantage. If tax authorities (like the IRS) decide to change the rules or classify box spread ETFs as generating ordinary income, BOXX would lose its primary advantage over cheaper alternatives like SGOV.

Delivers returns similar to 1-3 month U.S. Treasury bills using a tax-efficient options strategy (box spreads) instead of holding physical bonds.

Why This Week?

BOXX is a financial engineering masterpiece. It provides the risk-free yield of short-term Treasuries, but because it generates those returns through options contracts (box spreads), the gains are treated as capital gains rather than ordinary income. For high-tax bracket investors, this loophole can significantly increase after-tax yield compared to traditional T-bill ETFs like SGOV or BIL.

Key Metrics

Implied Yield

~5.2%

Expense Ratio

0.19%

Duration

< 0.25 yrs

AUM

$3.5B+

Tax Structure

Capital Gains

Top Holdings

2 holdings shown. Weights are approximate.

#NameWeight

SPXSPX Box Spreads (Options)

~95%

CASHCash & Equivalents

~5%

Pros & Cons

Strengths

Tax efficiency: Returns are capital gains instead of ordinary income/interest.
Returns closely track the risk-free rate of 1-3 month Treasury bills.
Virtually zero duration risk or interest rate risk on the principal.
Strong principal protection by mimicking very short-term fixed income.

Risks & Weaknesses

Regulatory Risk: The IRS could potentially close the tax loophole that makes BOXX attractive.
Higher expense ratio (0.19%) compared to direct T-bill ETFs like SGOV (0.07%).
Counterparty/Clearing risk: Relies on the OCC (Options Clearing Corporation) rather than the US Treasury directly.
Complexity: The underlying mechanism is hard to understand for average investors.

Alternatives Comparison

ETF	Name	TER	Focus
BOXXThis Week	Alpha Architect 1-3 Month Box ETF	0.19%	Delivers returns similar to 1-3 month U.S. Treasury bills using a tax-efficient options strategy (box spreads) instead of holding physical bonds.
SGOV	iShares 0-3 Month Treasury Bond ETF	0.07%	Holds physical 0-3 month Treasury bills
BIL	SPDR Bloomberg 1-3 Month T-Bill ETF	0.14%	Holds physical 1-3 month Treasury bills
SHV	iShares Short Treasury Bond ETF	0.15%	Holds Treasuries with less than 1 year to maturity

💬 Frequently Asked Questions

BOXX uses an options strategy called a 'Box Spread'. It involves buying a bull call spread and a bear put spread with the same expiration dates on the S&P 500 (SPX). This combination creates a risk-free payoff at expiration. By executing this trade, BOXX is essentially lending cash to the options market at the 'implied risk-free rate', which perfectly tracks the yield of short-term Treasury bills.

Taxes. When you hold a Treasury bill ETF like SGOV, the yield is paid out as monthly dividends (ordinary income), which is taxed at your highest marginal rate. BOXX generates its return through the appreciation of its options contracts. When you sell BOXX, the profit is treated as a capital gain, which usually has a much lower tax rate.

Almost, but not exactly. Treasury bills are backed by the full faith and credit of the US Government. BOXX is backed by the Options Clearing Corporation (OCC). While the OCC is considered systemically important and incredibly safe, it is technically a step below direct US Government backing.

Regulatory/Tax risk. The main appeal of BOXX is its tax advantage. If tax authorities (like the IRS) decide to change the rules or classify box spread ETFs as generating ordinary income, BOXX would lose its primary advantage over cheaper alternatives like SGOV.

Want to Explore Further?

BOXX launched recently, so try backtesting SMH or SOXX as semiconductor proxies, or explore our ETF database for alternatives.

Backtest SMH + SOXX ETF Explorer

Disclaimer: ETF of the Week is educational content only. It is not investment advice, a recommendation to buy or sell, or an endorsement of any fund. Past performance does not guarantee future results. Always do your own research and consult a financial advisor before investing.