iShares exposes the silent cost of sitting on cash

Americans holding large balances in traditional savings accounts may be paying a price that rarely feels obvious at first. While cash in the bank can feel safe, inflation can steadily reduce what that money can buy over time. 

Even when an account earns interest, the return may not be enough to keep pace with rising prices, creating a subtle loss that many households never notice until years later. A recent analysis from BlackRock’s iShares platform highlights how this hidden cost can affect investors and even everyday savers. 

The report shows how cash has performed against inflation, shifting Federal Reserve rates, and higher-yield alternatives that some account holders may be overlooking.

What BlackRock’s SGOV study reveals about the cost of idle cash

The iShares report draws a sharp line between the interest that everyday savers earn and the yields available on short-dated government debt, using fresh 2025 figures. Americans earn an average annual rate of 0.39% on their savings balances today, while the one-year Treasury yield reached 3.47% by year’s end, according to iShares.

The BlackRock unit drew its figures from Federal Deposit Insurance Corporation data via FRED, and Bloomberg market data, in its March 30, 2026 note. Expected 12-month inflation was running near 2.28%, meaning the typical saver earned less than a fifth of what was needed just to stay even, as iShares noted. 

“Short-term inflation noise is just that. It’s noise. The bigger mistake investors make is reacting to it…Selling out of equities because of a CPI print or making a dramatic shift in your portfolio based on one month’s data [is] usually how people hurt themselves investing in the market,” Doug Boneparth, CFP and founder of Bone Fide Wealth, told CNBC.

That is where the phrase “silent cost” earns its weight, because the nominal balance on your statement quietly grows while real buying power shrinks. “Inflation, the general increase in prices of goods and services over time, can quietly erode your purchasing power as idle cash may earn less interest than the rate of inflation,” product strategist Tom Fickinger wrote in the iShares report.

How savings accounts stack up against money market funds and Treasuries

Savings accounts at brick-and-mortar banks are generally protected by FDIC insurance up to $250,000 per depositor per bank.  This protection applies to principal balances held in insured institutions, according to the Federal Deposit Insurance Corporation. Interest rates are typically set by the bank and may adjust more slowly than broader market changes.

As a result, returns can lag behind higher-yielding cash alternatives during shifting rate environments. Money market funds tend to respond more directly to changes in short-term interest rates set by the Federal Reserve. Their yields often move more closely in line with monetary policy than those of traditional savings accounts.

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These funds are not FDIC-insured, but they are designed with regulatory safeguards aimed at stability under normal conditions. Some may also have higher minimum investments or temporary redemption limits during periods of market stress. Treasury bills are backed by the U.S. government and issued with very short maturities.

Interest earned is generally exempt from state and local income taxes, which can improve net returns. However, individual T-bills require reinvestment management upon maturity. Otherwise, cash may sit idle in a brokerage account between rollovers. SGOV is an ETF that holds U.S. Treasury securities maturing in three months or less.

How SGOV’s yield advantage works in today’s rate environment

Here are some ways SGOV’s yield advantage affects today’s rate environment.

Fed policy still anchors the short end of the curve

The Federal Reserve held its target range at 3.50% to 3.75% at its March 18, 2026, meeting, marking a pause following the late-2025 rate cuts. The committee signaled close attention to inflation and employment before any further policy move, according to the Federal Reserve statement.

Short-dated Treasury yields closely track the policy rate, which helps explain why the SGOV 30-day SEC yield stood at 3.55% as of April 15, 2026. Its 12-month trailing distribution yield sat higher at 3.95%, reflecting stronger rates during much of the past year, according to the iShares fund page.

Size and liquidity give it cash-like attributes

SGOV now holds more than $83 billion in assets and typically trades over $1 billion in shares each day, according to iShares. That kind of daily volume matters because it helps keep the bid-ask spread narrow, reducing your transaction cost whenever you buy or sell shares.

What the spread looks like on a real cash balance

Compare that to the 0.39% average that a standard savings account currently pays, and the gap approaches 316 basis points of yearly income foregone for the average saver. On a $50,000 cash balance, that gap translates into roughly $1,580 per year of extra pre-tax income that could have flowed into your account instead.

Scale that same math to $100,000, and the annual gap reaches around $3,160 of foregone pre-tax income, before any state tax benefit even enters the math. Even smaller balances feel the drag over time, since a $20,000 cushion held at the average savings rate yields roughly $630 each year relative to short Treasury yields.

Where SGOV can fall short and what every user should watch

The SGOV can experience a decline, and these are some things every user should pay attention to.

1. No cash alternative is completely risk-free,and SGOV is clear about how it differs from a federally insured deposit account. SEC disclosure filings for treasury ETFs carry a standard warning: “An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.” Unlike bank deposits, treasury securities held in ETFs are subject to market price fluctuations even though the underlying obligations are backed by the U.S. government.
2. Yield moves with policy and cannot be locked in. Its yield also moves with the federal funds rate, which means another round of Fed cuts would directly lower the monthly distributions you receive.

Allocate your funds more efficiently in 2026

Fund allocation in 2026 reflects a mix of roles rather than a single dominant option. Savings accounts continue to function as a primary source of immediate liquidity, while money market funds and products like SGOV are often used to access yields that track short-term rates more closely.

Returns for these vehicles are “driven less by steady income and more by shifting expectations around policy, inflation, and global capital flows” according to The Motley Fool’s treasury ETF analysis.

These allocations are not static. Changes in interest rates, tax treatment, and brokerage costs can all influence realized returns beyond the headline figures. As a result, the relative appeal of each option tends to shift over time alongside broader market conditions.

Related: iShares and two other ETFs emerge as crash shelters