A broker loan rate is the interest a brokerage charges when you borrow against the securities in your margin account. It’s built from two pieces: a benchmark rate and a spread the firm adds on top. As of early 2026, with the Wall Street Journal Prime Rate at 6.75% and the Secured Overnight Financing Rate around 3.65%, the all-in rate investors actually pay runs from roughly 5% to 12%, depending on how much they borrow and which broker they use.1Federal Reserve Bank of New York. Secured Overnight Financing Rate Data
How the Rate Is Built
Every broker loan rate starts with a published benchmark. The two most common are SOFR, currently near 3.65%, and the WSJ Prime Rate, which stood at 6.75% as of December 2025. On top of that benchmark, the brokerage adds a spread to cover its costs and profit. The spread is where firms differ most, and it’s the piece you can influence.
Brokerages price margin loans in tiers, with larger balances getting lower spreads. A loan under $25,000 might carry a spread of 4% or more above the benchmark. A balance over $500,000 might add only 1% to 1.5%. Two investors at the same firm can pay rates several percentage points apart based on balance alone.
What you hold in the account also affects the rate and how much you can borrow. Blue-chip stocks and U.S. Treasuries are easy to sell quickly, so brokers treat them as lower-risk collateral. Thinly traded stocks and certain corporate bonds raise the risk profile, which can push your rate up or reduce your borrowing limit. Some securities — options, low-priced stocks, newly issued IPO shares, and securities not listed on a major exchange — are classified as non-marginable, so you can’t borrow against them at all.
How the Interest Is Charged
Margin interest accrues daily on your outstanding debit balance, starting the day the credit is extended. Most brokerages calculate the daily charge using a 360-day year rather than 365 days. Interest is then posted to the account monthly and added to what you owe, so unpaid interest compounds over time.
To estimate a day’s interest, multiply your debit balance by the annual rate and divide by 360. At a 10% rate on a $100,000 balance, that works out to roughly $830 in interest each month before your investments earn anything.
What Rates Look Like Across Brokers
The gap between firms 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
Those differences add up quickly. On $300,000 borrowed for a year, the spread between the cheapest and most expensive broker in that comparison amounts to more than $15,000 in interest. Comparing rates before opening or funding a margin account is one of the few no-cost ways to reduce the cost of leverage.
The Conditions Attached to the Rate
The rate is only part of what you’re signing up for. Margin borrowing carries collateral requirements and forced-sale rules that can change what the loan actually costs you.
Initial and Maintenance Requirements
Federal Reserve Regulation T sets the initial margin requirement for equity securities at 50%. Buying $10,000 of stock on margin requires at least $5,000 of your own money.3Securities and Exchange Commission. Investor Bulletin: Understanding Margin Accounts Some brokerages require more, but none can require less.
After the position is open, FINRA Rule 4210 requires you to keep equity of at least 25% of the current market value of the securities held long in the account.4FINRA. FINRA Rule 4210 – Margin Requirements Equity means the market value of your securities minus what you owe. Most brokerages set their own house maintenance requirements above that floor, commonly between 30% and 40%, and can raise the threshold further for concentrated or volatile positions.
Margin Calls and Forced Sales
When your equity falls below the maintenance requirement, the broker issues a margin call for additional cash or marginable securities. The important detail, and the one investors most often miss, is that the broker doesn’t have to call first. FINRA’s own guidance states that a firm “don’t have to issue a margin call before selling securities in your margin account” and can sell “enough securities to completely pay off your margin loan, not just meet the margin call.”5FINRA. Know What Triggers a Margin Call
The broker also chooses which positions to sell. You don’t. Because forced liquidation tends to hit during declining markets, the sales usually lock in losses at bad prices. A “house call” is triggered at the firm’s internal threshold; a “regulatory call” occurs at the 25% FINRA floor. You’ll typically hit the house call first, which is the point: it gives the firm a buffer before the regulatory minimum is breached.
Tax Treatment of the Interest You Pay
Drawing on margin isn’t a taxable event — the proceeds are a liability, not income. The tax question is whether you can deduct the interest.
Interest on money borrowed to buy taxable investments counts as investment interest expense and is potentially deductible under 26 U.S.C. § 163(d), capped at your net investment income for the year. Any excess carries forward.6Office 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 unless you elect to include them, and that election means those gains lose their preferential rate and get taxed as ordinary income. The trade-off only pays off with substantial margin interest to absorb.
You calculate the deduction on IRS Form 4952 and report it on Schedule A as an itemized deduction, so you only benefit if you itemize.7Internal Revenue Service. Form 4952 – Investment Interest Expense Deduction If you used the borrowed funds for personal purposes rather than investments, the interest isn’t deductible at all. The IRS traces how the proceeds were used, not the label on the loan.
One boundary worth flagging: a securities-backed line of credit (SBLOC) is a different product. SBLOCs are classified as non-purpose credit under Federal Reserve rules, meaning the proceeds can’t be used to buy or carry securities or to repay a margin loan.8Regions Bank. SBLOC 101 – Guide to Securities-Based Lines of Credit If you see an SBLOC rate advertised, it isn’t a broker loan rate in the margin sense.
When the Rate Understates the Real Cost
Leverage cuts both ways. A 10% gain on a fully margined position doubles your return on the money you put in. A 10% loss wipes out twice as much of your own equity. In a steep decline, losses can exceed your original investment, and you still owe the broker the remaining balance.
Interest is also easy to underestimate over time. Because most firms post interest monthly and add it to the debit balance, the cost itself generates more cost. In a flat or declining market, that drag compounds against you while the securities backing the loan aren’t producing returns to offset it.
Short-term borrowing against a diversified portfolio for a defined purpose can be a reasonable use of a margin account. Borrowing heavily, holding indefinitely, and ignoring maintenance thresholds is how portfolios get liquidated at the bottom of a selloff — no matter how attractive the headline rate looked when the loan was drawn.