ISTB vs. SCHO: Two "Short-Term Bond" ETFs That Aren't the Same Bet

Same label, different paper. iShares' ISTB and Schwab's SCHO sit side by side in fund menus and "which is better" threads, and it is tempting to treat them as interchangeable and just grab the cheaper fee. Don't. They are built from different bonds, and "better buy" depends on what job this money is doing — not on the sticker price, and not on last year's return.

Put the card on the table before picking a side. Both are passively managed, U.S. short-duration bond funds from two of the largest asset managers, both are cheap, and both are liquid enough for any retail size. But the ingredients are different:

	ISTB (iShares)	SCHO (Schwab)
Tracks	Bloomberg U.S. Universal 1-5 Year	Bloomberg U.S. Treasury 1-3 Year
Maturity window	1-5 years	1-3 years
What it actually holds	~57% Treasuries, ~36% corporate, rest agency/securitized	100% U.S. Treasuries
Rate sensitivity	Higher — 1-5 yr window (~2.7 yr duration)	Lower — 1-3 yr window
Fee	0.06%	0.03%
Current yield	~4.3%	~3.9%
Size	~$5 billion	~$15 billion

The title asks a head-to-head question. The honest answer is that these are not truly head-to-head on one score, because they carry different risk budgets. That distinction is the whole story.

The card: one is a parking lot, the other is a workhorse

SCHO is the safest thing in the short bond corner. It holds nothing but U.S. Treasury securities with one to three years left to maturity, and it costs 0.03% a year to run — the cheapest tier in the space. It is a capital-preservation tool: short duration means the share price barely moves when rates wobble, and 100% government paper means there is no issuer to default. Its job is to sit in the account as a cash equivalent and pay out a steady, boring ~3.9% without asking you to think hard. It is roughly three times larger than ISTB (~$15 billion versus ~$5 billion), which keeps it deeply liquid.

ISTB is a diversified short-term bond fund, not a Treasury fund. It spreads a 1-5 year maturity window across investment-grade paper: roughly 57% Treasuries, about 36% corporate bonds, and the rest agency and securitized debt. It costs a little more (0.06%) and reaches out to a longer part of the curve (~2.7 years of effective duration versus a fund capped at three years), so it is a bit more sensitive to both rates and credit. Its job is the standard "short bond sleeve": a diversified allocation that earns more income than pure Treasuries in exchange for a small, managed dose of credit risk and a little extra rate exposure.

Give each 100 paper points at the latest close and you are not really running a race — you are choosing a role. The scoreboard that matters here is not total return; it is the mechanism board.

Where the extra income comes from

The number that carries the whole comparison is the yield gap: ISTB pays roughly 4.3%, SCHO roughly 3.9%, a spread of about 40 basis points. That is not luck and it is not a data glitch. It is the price of the credit inside ISTB.

Corporate and agency bonds pay more than Treasuries of the same maturity because the issuer is not the U.S. government. By holding about 36% of the fund in that higher-paying paper, ISTB collects a spread — typically on the order of 20 to 40 basis points over equivalent Treasuries — and passes some of it through to you as extra yield. SCHO, holding only government debt, gives that spread up. You get your extra income by accepting that, in a stress year, the corporate and agency slice can widen and drag the fund more than a pure Treasury fund does. ISTB's longer 1-5 year window adds a second, smaller reason its price moves a touch more than SCHO's.

That trade-off is the entire economic disagreement between the two funds: SCHO says "zero credit risk, shortest rate exposure, lowest cost, and accept the lower yield." ISTB says "take on some credit and a bit more duration, pay a tiny bit more in fees, and collect a little more income." Pick the one whose risk appetite matches yours.

The rule the title leaves out

There is a second, quieter difference that the "which is cheaper" framing misses: taxes. Both funds are federally taxable — neither is a municipal fund. But the income on U.S. Treasuries is generally exempt from state and local income tax, while corporate and agency interest is not. SCHO, being all Treasuries, delivers income that is generally state-tax-exempt. ISTB, with a large corporate and agency portion, delivers income that is more fully taxable in a state.

In an account where you owe state income tax, that quietly narrows ISTB's 40-basis-point yield edge. The after-state-tax gap is smaller than the headline gap suggests — and for some state-taxpaying investors the advantage can flip. Before you choose on yield, decide which side of the tax line your money lives on. It is the hidden rule that the sticker-price comparison never shows.

Verdict

There is no universal winner, and pretending there is one is how readers get the wrong fund. SCHO is the cleaner tool for the pure-safety job: parking cash, keeping a conservative anchor, or holding short-term money you want to see move as little as possible. ISTB is the tool for the income job: a diversified short bond allocation where you are comfortable with small credit risk and a bit more rate sensitivity in order to collect a little more yield.

The design lesson is the one that should outlast this matchup. "Short-term bond" is a category, not a risk budget. Two funds can wear the same label, cost almost the same, and still be different instruments — one a Treasury parking lot, one a blended credit fund that pays for the credit it takes. Read the holdings, not the label, and match the fund to the job the money is doing. That is the decision that actually moves your odds, and it is the one the title's framing was too small to hold.