What Is BIL? SPDR Bloomberg 1-3 Month T-Bill ETF

BIL is the SPDR Bloomberg 1-3 Month T-Bill ETF, issued by State Street Global Advisors. It tracks the Bloomberg 1-3 Month U.S. Treasury Bill Index, which holds U.S. Treasury bills with one to three months remaining until maturity. The expense ratio is 0.1356%.

The fund exists to do one narrow job: hold cash-like Treasury exposure that stays stable in price while earning prevailing short-term rates. Because the bills mature so quickly, BIL carries almost no interest-rate risk and, being backed by the U.S. Treasury, almost no credit risk. Investors and corporate treasurers use it as a place to park money between other decisions.

Approximate weights as of mid-2026; refresh quarterly from State Street (SSGA)'s fund page. Each ticker links to its individual stock guide in Walnut.

BIL holds a rolling ladder of U.S. Treasury bills, each maturing within one to three months, plus a small cash residual. There are no corporate bonds, long-dated Treasuries, or equities in the fund. As bills mature, the proceeds are reinvested into freshly issued short-dated bills, which keeps the average maturity inside the one-to-three-month band.

This structure is why BIL's yield reprices so quickly. The 30-day SEC yield sits near 4.2% in mid-2026, but that number tracks short-term Treasury rates and Federal Reserve policy closely. When the Fed raises rates, BIL's income rises within weeks; when it cuts, the income falls just as fast.

The closest competitor is SGOV, the iShares 0-3 Month Treasury Bond ETF. Both hold ultra-short Treasury bills and behave almost identically day to day. The clearest difference is cost: SGOV carries a lower expense ratio than BIL's 0.1356%. In a near-zero-duration instrument where yields are essentially the same, that fee gap is the main reason many buyers now default to SGOV.

BIL's advantages are its long track record since 2007 and its very deep liquidity from roughly $47 billion in assets, which some large or institutional buyers value. For most individual investors, the two are interchangeable, and the choice usually comes down to fee and whatever their broker or existing holdings favor.

BIL's total return is essentially its yield, since the price barely moves. In periods of higher short-term rates its return has been strong for a cash instrument, and in near-zero-rate periods it earned almost nothing. Its return path is therefore a direct reflection of where the Fed sets policy.

Looking ahead, the key variable is the direction of short-term rates. If the Federal Reserve cuts, BIL's yield falls with it; if rates stay elevated, BIL keeps paying a competitive cash yield. It will never deliver equity-like growth, and that is by design. Its job is stability and liquidity, not appreciation.

BIL fits investors who want a stable, liquid cash sleeve that earns short-term Treasury rates without the price swings of longer bonds. Common uses include holding an emergency reserve, parking proceeds from a sale, or keeping dry powder while waiting to deploy into other assets. It is a core cash position, not a return driver.

The tradeoffs are that BIL will not keep pace with stocks over time and its income drops when the Fed cuts rates. Walnut is not an investment adviser and this is not a recommendation. Whether BIL suits you depends on your own cash needs, time horizon, and how much of your portfolio you want in stable, low-return assets.

BIL trades like any stock during market hours. You can buy it on brokers such as Robinhood, Fidelity, Schwab, and Public, and many of these support fractional shares so you can invest a set dollar amount rather than whole shares. There is no minimum beyond the price of a single share, and no lockup.

If you already hold positions elsewhere, you can connect your brokerage to Walnut to track BIL alongside the rest of your portfolio, see how much of your money sits in cash-like assets, and monitor how that allocation changes over time. Trade execution always stays at your own broker.

BIL is a plain cash-alternative ETF: a basket of one-to-three-month Treasury bills with almost no duration and no credit risk. Its yield tracks short-term Treasury rates, so it rises and falls with Fed policy. It plays a core cash-sleeve role, not a growth or income-growth role. SGOV offers the same exposure at a slightly lower fee.

Whether BIL is worth buying today depends more on your time horizon and what you already hold than on any single call. We walk through valuation, concentration, and what would have to be true for it to outperform from here in is BIL a buy?

BIL yields ~4.2% (30-day SEC yield, moves with short-term rates) as of mid-2026, paid by passing through the dividends of its underlying holdings. For the payout schedule, history, and how the distributions are taxed, see BIL dividend: yield and schedule.