A short rebate is the interest your broker credits back to you on the cash collateral that sits behind a short sale. When you borrow shares and sell them, the proceeds are held as collateral for the lender, who earns overnight interest on that cash and passes a share of it back to you after taking a spread. Whether you actually see any of that money, and how much, depends on the overnight benchmark rate, how scarce the stock you borrowed is, and the terms of your brokerage account.
Where the Money Comes From
Shorting a stock means selling shares you don’t own. You borrow them from someone who does, sell them in the open market, and owe those shares back later. The cash from the sale doesn’t come to you to spend. It sits with the lender as security against the day you have to return the stock.
Securities lending convention is for the borrower to post cash collateral worth 102 percent of the loaned shares’ market value for domestic securities, and 105 percent for international ones.1Federal Reserve Bank of New York. The Use of Collateral in Bilateral Repurchase and Securities Lending That cushion covers daily price moves before the collateral can be adjusted. The position is marked to market each day: if the stock rises, you post more; if it falls, excess collateral may be released.
While the lender is holding your cash, it is earning interest on it overnight. The rebate is the slice of that interest paid back to you.
How the Rate Is Calculated
The calculation starts with an overnight benchmark. Historically that was the Effective Federal Funds Rate, which measures unsecured overnight lending between banks. More recently, the Secured Overnight Financing Rate, which reflects borrowing cash overnight against Treasury collateral, has gained ground. Both are in active use, and the lending desk picks whichever fits its pricing model.2Office of Financial Research. OFR Short-term Funding Monitor – Federal Reserve Bank of New York Reference Rates
From that benchmark the broker subtracts a spread, sometimes called a haircut, to cover share location, loan management, and operational risk. For easy-to-borrow names the spread typically runs between 25 and 100 basis points, wider at smaller brokerages or for smaller accounts. What’s left is your base rebate rate, annualized and credited daily.
A rough example. If the overnight benchmark is 4 percent and the broker takes a 0.75 percent spread, the base rebate is 3.25 percent. That number moves whenever the central bank adjusts its target range. As of late 2025 the federal funds rate was around 3.7 percent and had been trending lower from its 2023 peak.3Federal Reserve Bank of St. Louis. Federal Funds Effective Rate (FEDFUNDS)
Then the stock-specific borrow fee comes off the top. Add a 0.25 percent borrow fee to the example above and the net rebate works out to 3 percent annualized.
When the Rebate Turns Negative
The securities lending market splits roughly in two. General collateral stocks are the ones every lender has and no borrower is desperate for, which is about 90 percent of all lendable securities. Borrow fees stay under 100 basis points, so the net rebate stays close to the base rate. Shorting a large-cap name with high float and no unusual demand means borrowing at general collateral rates.
Hard-to-borrow securities, sometimes called “specials,” are stocks with limited float, high short interest, or sudden demand from multiple borrowers. The lending desk charges a borrow fee on top of the benchmark-minus-spread calculation, and that fee can be steep enough to flip the math.
When the borrow fee exceeds the base rebate, the rebate goes negative. Instead of earning interest on your collateral, you pay to keep the position open. The IRS recognizes this directly, defining a “borrow fee (including negative rebate)” as a fee paid in connection with a securities lending transaction.4Internal Revenue Service. Notice 25-63 – Source of Certain Borrow Fees A stock with a 12 percent annualized borrow fee and a 3.25 percent base rebate costs you a net 8.75 percent per year. On a $50,000 short, that’s roughly $4,375 a year, deducted daily from your cash balance or added to your margin debt.
Borrow fees on popular short targets can spike without warning when share recalls tighten supply, and there’s no cap. Check the current borrow rate before entering and watch it daily if you’re shorting outside the general collateral universe.
Who Actually Receives a Rebate
Not everyone who shorts a stock gets paid a rebate. Account type, size, and program enrollment all matter.
Institutional investors and hedge funds negotiate rebate terms directly through prime brokerage agreements. The split is part of a broader relationship covering execution, clearing, and financing, which gives these clients leverage to push for higher rebate percentages and tighter spreads. Qualified Institutional Buyers, entities owning and investing at least $100 million in securities on a discretionary basis, access the most favorable terms.5eCFR. 17 CFR 230.144A – Private Resales of Securities to Institutions
Retail traders face a higher bar. FINRA sets a $2,000 minimum equity requirement to open a margin account at all.6FINRA. FINRA Rule 4210 – Margin Requirements But clearing the regulatory minimum doesn’t entitle you to a rebate. Most brokers reserve rebate payments for clients with substantially larger balances, often $100,000 or more, and many require enrollment in a specific program such as a Fully Paid Lending or Yield Enhancement arrangement.
What You Give Up to Earn One
Enrolling in a lending program means signing a lending agreement, and the agreement carries trade-offs that are easy to miss. You lose proxy voting rights on any shares that are out on loan. Dividends paid while your shares are lent out arrive as substitute payments rather than actual dividends.7BNY Pershing. Fully Paid Securities Lending
SIPC coverage is the other quiet concession. SIPC protects what the broker was holding for you when a liquidation begins.8Securities Investor Protection Corporation. What SIPC Protects Shares out on loan may not be in your account at that moment, so if the broker fails before returning them, the collateral posted by the borrower may be your only recourse. FINRA requires brokers to disclose that “the provisions of the Securities Investor Protection Act of 1970 may not protect the customer with respect to the customer’s securities loan transaction,” along with collateral limitations and any restrictions on selling loaned securities.9FINRA. Regulatory Notice 10-03
How Rebates and Substitute Payments Are Taxed
Two tax issues come up around short rebates and lending, and they catch people out at filing time.
If you’re the short seller and the stock pays a dividend during your loan, you owe the lender a substitute payment equal to the dividend. You can deduct that payment as investment interest on Schedule A, but only if you keep the short sale open for at least 46 days. Close before the 46th day and you can’t deduct the payment; you add it to the cost basis of the shares you use to close the position instead.10Internal Revenue Service. Publication 550, Investment Income and Expenses
On the lender’s side, substitute dividend payments received on loaned-out shares are not qualified dividends. The IRS classifies them as “Other income” on Schedule 1, line 8z, which means they’re taxed at ordinary income rates even if the underlying dividend would have qualified for preferential treatment.10Internal Revenue Service. Publication 550, Investment Income and Expenses Lenders who don’t realize their shares went out on loan sometimes find out at tax time, when the 1099 shows substitute payments instead of qualified dividends.