Updated October 23, 2026 from live rates
BOXX vs Treasury bills: which keeps more after tax?
It depends on your taxes. At today's rates, 3-month T-bill keeps more in the 24% bracket with 5% state tax or 9.3% state tax. BOXX (over a year) keeps more in the other 7 scenarios. The gap is up to $2,587 a year on $500,000.
After-tax yield by tax situation
Yield you keep after federal and state income tax, at today's rates. The last column is the yearly gap between the best and second-best on $500,000. The 3.8% net investment income tax is left out; it lowers every taxable option by the same share.
| Federal bracket, state tax | BOXX (over a year) | 3-month T-bill | Yearly gap |
|---|---|---|---|
| 24%, no state tax | 3.37% | 3.21% | $836 |
| 24%, 5% state | 3.18% | 3.21% | $156 |
| 24%, 9.3% state | 3.01% | 3.21% | $1,010 |
| 32%, no state tax | 3.37% | 2.87% | $2,524 |
| 32%, 5% state | 3.18% | 2.87% | $1,532 |
| 32%, 9.3% state | 3.01% | 2.87% | $678 |
| 37%, no state tax | 3.18% | 2.66% | $2,587 |
| 37%, 5% state | 2.98% | 2.66% | $1,595 |
| 37%, 9.3% state | 2.81% | 2.66% | $741 |
What's different
| BOXX (over a year) | 3-month T-bill | |
|---|---|---|
| What it is | Box-spread ETF, held over a yearBOXX, Alpha Architect 1-3 Month Box ETF | 3-month Treasury billBought at auction or in your brokerage, held to maturity |
| Rate today | 3.97%Estimated: 2-month T-bill minus expense ratioEstimate, October 23, 2026 | 4.22%Par yield, held to maturityVerified October 23, 2026 |
| Getting your money | Sell any trading day; settles next business day | Matures in 3 months; can be sold any day at market price |
| Protection | Exchange-traded fund holding options spreads, not FDIC-insured | Backed by the U.S. government |
| State income tax | Taxed as a capital gain | Exempt |
BOXX doesn't publish a yield, so its rate here is an estimate: the 2-month Treasury yield minus the fund's 0.1949% expense ratio. Held over a year, its return has been taxed as a long-term capital gain rather than interest, which is the whole case for it in high brackets. The IRS could treat box-spread returns differently; that risk is why we label it an estimate.
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