A broker loan rate is the interest rate your brokerage charges when you borrow against the securities in your margin account. It’s built in two pieces: a benchmark rate such as the Secured Overnight Financing Rate (SOFR) or the Wall Street Journal Prime Rate, plus a spread the broker adds on top. As of early 2026, WSJ Prime sat around 6.75% and SOFR around 3.65%, and the all-in rate investors actually paid ran from roughly 5% to 12% depending on how much they borrowed and which firm they used.1Federal Reserve Bank of New York. Secured Overnight Financing Rate Data
The Two Pieces That Make Up Your Rate
Every broker loan rate has the same structure. The benchmark moves with the broader interest rate environment and is the same for everyone. The spread is where brokerages compete, or don’t. Two investors at two different firms can borrow against identical portfolios and pay rates that differ by five percentage points or more, entirely because of the spread.
Spreads are tiered by balance. Borrow under $25,000 and the spread might be 4% or more above the benchmark. Borrow over $500,000 and the spread can drop to 1% to 1.5%. The logic is straightforward: larger loans cost the broker about the same to service as small ones, so the firm can charge a thinner margin and still make money.
What you’re borrowing against matters too. Blue-chip stocks and U.S. Treasury securities are liquid and easy to sell if the loan goes bad, so brokers treat them as lower risk and may offer a better rate or a higher borrowing limit. Thinly traded stocks and certain corporate bonds carry more risk to the lender, which can push your rate higher or cap how much you’re allowed to borrow against them.
How Interest Accrues
Margin interest accrues daily on your outstanding debit balance, starting the day the credit is extended. Most brokerages use a 360-day year rather than 365 when calculating the daily charge. Interest posts to your account monthly, and because unpaid interest is added to what you owe, the balance compounds. A quick estimate of your daily cost: multiply the debit balance by your annual rate, then divide by 360.
What Rates Actually Look Like
The spread between brokers is wider than most investors expect. As of March 2026, on a $25,000 margin balance, Interactive Brokers charged about 5.14%, while Fidelity, Schwab, and Vanguard all fell between roughly 11.3% and 11.95%. On a $300,000 balance, Interactive Brokers dropped to 4.81% and the full-service firms came down to about 10%.2Interactive Brokers. US Margin Loan Rates Comparison
The dollars add up quickly. On $300,000 borrowed for a year, the gap between the cheapest and most expensive broker in that comparison amounted to more than $15,000 in interest. Comparing published margin schedules before you open or fund an account is one of the few free ways to cut the cost of leverage.
What Moves Your Rate Up or Down
Three levers determine where you land within a broker’s schedule.
Balance size is the largest. Rate schedules are published in tiers, and crossing a tier boundary can drop your rate noticeably. If you’re close to a threshold, consolidating loans or moving assets from another account may pay for itself.
Collateral quality is the second. A margin balance backed by diversified large-cap holdings is a different risk to the broker than one backed by a concentrated position in a volatile small-cap. Firms may raise requirements or apply worse pricing for accounts concentrated in a single stock or sector.
The firm itself is the third and often the biggest. Discount and electronic brokers built around margin lending typically publish rates several points below full-service firms at every tier. If margin borrowing is a real part of your strategy rather than an occasional short-term draw, the choice of brokerage is the single biggest input into what you’ll pay.
Why the Rate Matters More Than It Looks
A double-digit rate on a five-figure balance is not a background cost. At 10% on a $100,000 margin balance, you’re paying roughly $830 a month in interest before your investments earn anything. In a flat or down market, that drag compounds against you, because unpaid interest gets rolled into the debit balance and starts generating interest of its own.
The rate also shapes what strategies actually make sense on margin. A short-term draw to bridge a settlement or take advantage of a specific opportunity looks very different at 5% than at 12%. Long-term buy-and-hold on margin at a double-digit rate needs the portfolio to consistently outrun the interest, which is a harder bar than most investors credit.
Beyond the interest itself, borrowing on margin carries risks the rate doesn’t capture. Federal Reserve Regulation T requires at least 50% equity when you open a position, and FINRA Rule 4210 requires you to maintain equity of at least 25% of the market value of securities held long, with most firms setting house minimums of 30% to 40%.3Securities and Exchange Commission. Investor Bulletin: Understanding Margin Accounts4FINRA. FINRA Rule 4210 – Margin Requirements Fall below the maintenance threshold and the broker can sell your holdings, without advance notice, to bring the account back into compliance.5FINRA. Know What Triggers a Margin Call Forced liquidation almost always happens in falling markets, which is when selling locks in the worst losses.
Margin Loans and SBLOCs Are Not the Same Product
A securities-backed line of credit (SBLOC) also uses your investments as collateral, but it is priced and regulated differently, and searchers often confuse the two.
The core distinction is what you’re allowed to do with the money. Margin loans exist so you can buy more securities. SBLOCs are classified as non-purpose credit under Federal Reserve rules, meaning the proceeds can be used for almost anything except purchasing or carrying securities or repaying an existing margin loan.6Regions Bank. SBLOC 101 – Guide to Securities-Based Lines of Credit SBLOC rates are often pegged to SOFR, which moves daily, while margin loans commonly reference prime, which changes less often. SBLOCs also typically require monthly interest payments, whereas many margin loans let interest accrue against the balance.
The Interest You Pay May Be Partially Deductible
Borrowing on margin isn’t a taxable event on its own; the loan is a liability, not income. The tax question is what happens to the interest.
Interest on money borrowed to buy taxable investments counts as investment interest expense and is potentially deductible. Under 26 U.S.C. ยง 163(d), the deduction is capped at your net investment income for the year, with any excess carrying forward.7Office of the Law Revision Counsel. 26 USC 163 – Interest Net investment income includes interest, ordinary dividends, annuities, royalties, and net short-term capital gains. Long-term capital gains and qualified dividends are excluded by default; you can elect to include them, but doing so strips their preferential rate.
You calculate the deduction on IRS Form 4952 and report it as an itemized deduction on Schedule A, so it only helps if you itemize.8Internal Revenue Service. Form 4952 – Investment Interest Expense Deduction If you used the borrowed money for personal purposes rather than to buy investments, the interest isn’t deductible at all. The IRS traces the use of proceeds, not just the existence of the loan.