Stock Borrow Fees and Hard-to-Borrow Stocks: What Shorting Really Costs

In January 2021 it cost about 25% a year to borrow GameStop shares, and in the second quarter of 2020 more than 100%, according to the SEC staff report on early-2021 market conditions. The same report put the average lending fee across stocks from 2007 to 2018 at 1.5%. That spread is the subject of this guide. Every short sale depends on a loan of shares, and the price of that loan, the borrow fee, is normally a rounding error. In a crowded short it can decide the whole trade. Part of the institutional money flow series.

What is a stock borrow fee?

A stock borrow fee is the annualized rate a short seller pays to borrow shares, charged daily on the current value of the loan. If you short $100,000 of stock with a 2% fee, you pay about $5.48 a day for as long as the position is open.

You can’t sell what you don’t have, so a short seller first borrows the shares. The lender gets a fee and keeps the economic exposure: the borrower must pay the lender any dividends, as the SEC’s investor bulletin on short sales notes. The fee moves daily with supply and demand, so the rate you see when you open a short is not locked in.

How the fee is quoted depends on the collateral. The Office of Financial Research’s 2016 survey of agent securities lending explains that when collateral is non-cash, the borrower pays a lending fee. When collateral is cash, the lender instead pays the borrower a rebate rate on that cash, and the lender’s return is what it earns on the cash minus the rebate. For a stock in high demand the rebate “can be low or even negative,” meaning the borrower pays the lender. A negative rebate is a borrow fee by another name.

How does securities lending work?

Securities lending runs through a chain: owners lend shares through an agent lender or prime broker to a borrower, who posts collateral and sells the shares in the market.

• Lenders are mostly large, long-term holders: pension funds, mutual funds, ETFs, insurers and endowments. Individuals can lend through fully paid lending programs at their brokers.
• Agent lenders, often custodian banks, lend on behalf of those owners, collect the fee and reinvest cash collateral. Broker-dealers lend from margin accounts and from fully paid programs.
• Borrowers are mainly broker-dealers and prime brokers, who on-lend to hedge funds and use shares to cover their own short sales and market-making.
• Collateral is usually 102% to 105% of the loaned securities’ value, the range the OFR survey reports as standard market practice, marked to market daily.

The market is large and mostly idle. The OFR survey found about $9.4 trillion of securities available to lend through participating agent lenders in 2015, with about $1 trillion actually on loan. And most loans are short-lived by contract: 81% were open loans that could be terminated at any time. That last fact explains recall risk, covered below.

What is the difference between easy to borrow and hard to borrow?

Easy-to-borrow stocks have far more lendable supply than short demand; hard-to-borrow stocks have demand close to or above the supply. The category drives fee, availability and risk.

Most large-cap stocks trade as “general collateral”: lots of index funds own them and lend them, so fees are low and stable, and brokers keep an easy-to-borrow list that lets you short without a per-order check. A stock becomes “warm” and then “special” or hard to borrow as short demand eats into the pool. Common causes:

• Small or locked float: recent IPOs, insider-heavy ownership, lockups.
• Retail-heavy ownership: shares in cash accounts can’t be lent unless the owner opts into a lending program.
• Crowded bearish thesis: a published short report or a popular short theme.
• Corporate events: convertible issues and stock-for-stock mergers, where arbitrage funds short against their positions.

Easy and hard to borrow are broker labels, not regulatory categories. Each prime broker sets its own lists daily from its own supply.

Why do borrow fees spike?

Because the fee is set at the margin. While plenty of shares are available, lenders compete and fees stay low; once nearly all lendable shares are out, the last borrower sets the price, and that price can jump.

The chart is illustrative, not a market model, but its shape is the useful part. Fees are flat across a wide range of utilization (shares on loan divided by shares available to lend), and then curve up sharply as utilization nears 100%. Two practical implications follow. First, a stock’s fee can go from negligible to painful in days, with no change in the company, just because more shorts arrived or a big lender stopped lending. Second, a high fee is itself information: it tells you the short side is crowded, which is one of the ingredients of a short squeeze. Read it alongside short interest, which is published with a lag, while borrow fees move daily.

What do Reg SHO locate and fails-to-deliver rules require?

Regulation SHO requires a locate before a short sale and a prompt close-out if the short seller fails to deliver. Those two rules are why borrow availability is a real constraint, not a formality.

• Locate (Rule 203(b)). According to the SEC’s Key Points About Regulation SHO, a broker-dealer must have “reasonable grounds to believe that the security can be borrowed so that it can be delivered on the date delivery is due” before effecting a short sale, and the locate must be made and documented first. For easy-to-borrow names the broker’s list serves as the locate; for hard-to-borrow names it may need a specific borrow for each order.
• Close-out (Rule 204). If a short sale fails to deliver, the clearing firm must close out the fail by buying or borrowing shares by the beginning of regular trading on the settlement day after the settlement date.
• Threshold securities (Rule 203(b)(3)). Stocks with fails of at least 10,000 shares and 0.5% of shares outstanding for five consecutive settlement days go on a threshold list; fails that persist 13 consecutive settlement days must be closed out immediately.

The SEC publishes fails-to-deliver data twice a month: the balance of fails recorded in the National Securities Clearing Corporation’s system, aggregated over all members, by security. Fails can come from long sales as well as short, and from ordinary operational delays, so a spike in fails is a prompt to look closer, not proof of “naked shorting.”

More lending data is planned but delayed. In October 2023 the SEC adopted Rule 10c-1a, which requires loans to be reported to FINRA and loan-rate data to be made public. Under SEC exemptive relief, reporting now starts in September 2028 and public dissemination in March 2029, as McDermott Will & Schery summarizes. Until then, borrow fees come from brokers and commercial data vendors.

What happens when borrowed shares are recalled?

The lender can usually end the loan at any time, and if your broker can’t replace the shares, it can buy them in the market and close your short without asking. That is a buy-in.

The OFR survey’s finding that 81% of loans were open and terminable at any time is the root of this risk. Lenders recall shares to sell them, to vote them at a shareholder meeting, or because a fully paid lender moved or sold the position. In an easy-to-borrow stock the broker simply finds another lender. In a hard-to-borrow stock there may be none, and the buy-in happens at whatever the price is, which during a squeeze is the worst possible time. Recalls, buy-ins and rising fees tend to arrive together, because all three are symptoms of the same shortage.

What does a borrow fee cost a short seller? A worked example

Here is the full cost of carrying a hard-to-borrow short for three months, step by step (illustrative numbers).

1. Position. Short 2,000 shares at $40, a $80,000 position. Borrow fee: 40% a year, charged daily on the current value.
2. Daily fee. $80,000 × 0.40 ÷ 365 = about $87.67 a day.
3. Three months (91 days), price flat. $87.67 × 91 = about $7,978, almost 10% of the position.
4. Break-even. The stock must fall about $3.99 a share, to roughly $36.01, before the trade makes money, before dividends and commissions.
5. If the fee doubles. At 80% for the last month (30 days) the fee rises to about $175 a day, adding about $2,630. Break-even moves to roughly $34.70.
6. If the price rises. At $50 the position is worth $100,000 and the 40% fee costs about $110 a day. A rising price makes a short more expensive to hold, on top of the loss.

Should you lend your shares through a fully paid lending program?

Fully paid lending lets you earn part of the borrow fee on shares you own outright, but loaned shares lose SIPC protection and voting rights while on loan, and payments in lieu of dividends are taxed as ordinary income.

Brokers invite customers with fully paid shares, often in hard-to-borrow names, to lend them in exchange for a share of the fee. FINRA’s December 2023 settlement with M1 Finance lays out the trade-offs: customers who lend “lose, for the duration of the securities loan, both SIPC protection and voting rights,” and payments in lieu of dividends “are taxed as regular income, like nonqualified dividends.” FINRA also found that the firm had misstated to more than 1.5 million retail investors the compensation they would receive, a reminder to check the actual split.

Normally, SIPC protects up to $500,000 per customer, including $250,000 of cash, if a member brokerage fails. Loaned shares fall outside that; you rely on the collateral the broker posts for you and the broker’s financial strength.

For holders of a large single-stock position, lending can be worthwhile in a hard-to-borrow name, but check four things first:

• The split. What percentage of the fee you receive, and how it is calculated.
• Collateral. Where it is held, in what form, and at what percentage of value.
• Dividends and tax. If you hold for qualified dividend treatment, payments in lieu may cost you more in tax than the lending income.
• Your plans. Recall timing before a sale, a 10b5-1 plan execution, or an options strategy such as a collar on the same shares.

There is also a quieter point: lending your shares adds to the supply that lets others short the stock you own. Whether that matters to you is a judgment call, but it is part of how crowded trades are financed.

What is a checklist before shorting or lending?

1. Check whether the stock is on your broker’s easy-to-borrow or hard-to-borrow list today.
2. Get the current borrow fee or rebate and its recent trend, not just today’s rate.
3. Compute the monthly hurdle (annual fee ÷ 12) and the break-even price for your planned holding period.
4. Check short interest and days to cover for crowding.
5. Check the SEC fails-to-deliver data and threshold lists for persistent delivery problems.
6. Plan for recall: what you will do if the broker closes the position.
7. Compare with a defined-risk put spread that needs no borrow.
8. If lending: read the fee split, collateral terms, SIPC disclosure and tax treatment first.

Frequently asked questions

Key takeaways

1. Every short sale requires a loan of shares; the borrow fee is the price of that loan, charged daily on its value.
2. Lenders (pensions, funds, ETFs and individuals) lend through agent lenders or prime brokers against collateral of about 102–105%.
3. Most stocks are easy to borrow and cheap; fees spike when short demand nears the lendable supply.
4. Regulation SHO requires a locate before a short sale and a prompt close-out of fails to deliver.
5. Most loans are open and recallable at any time, so hard-to-borrow shorts face buy-in risk.
6. Fully paid lending pays individuals for lending shares but removes SIPC protection and voting rights while on loan.
7. Factor the borrow fee into any short’s break-even; in hard-to-borrow names it can dominate the trade.

Sources and method

1. Office of Financial Research, Working Paper 16-08, A Pilot Survey of Agent Securities Lending Activity (Aug 2016) — lending chain, rebates, margins, size of the market
2. SEC, Key Points About Regulation SHO — locate, close-out and threshold securities
3. SEC, Fails-to-Deliver Data — twice-monthly fails data from NSCC
4. SEC press release 2023-220, Rule 10c-1a (Oct 13, 2023) — securities lending transparency rule
5. McDermott Will & Schery, SEC Provides Two-Year Extension on Short Sale Reporting and Securities Lending Compliance — 10c-1a compliance dates moved to 2028
6. FINRA, Letter of Acceptance, Waiver and Consent, M1 Finance LLC (Dec 2023) — fully paid lending: loss of SIPC protection and voting rights, tax on payments in lieu
7. SIPC, What SIPC Protects — $500,000 limit including $250,000 cash
8. Investor.gov, Investor Bulletin: An Introduction to Short Sales — borrowing costs and buy-in risk
9. SEC, Staff Report on Equity and Options Market Structure Conditions in Early 2021 (Oct 14, 2021) — GameStop borrow cost; average lending fee 2007–2018

Chart 1 is a Proflex diagram based on the roles described in OFR Working Paper 16-08. Chart 2 is an illustrative fee curve, not market data: fee = 0.25% a year up to 50% utilization, then rising exponentially; real fees are set daily by supply and demand. Chart 3 is a Proflex framework; easy-to-borrow and hard-to-borrow are broker labels, not regulatory categories. The worked example uses hypothetical numbers. Rule 10c-1a dates reflect SEC relief as reported in October 2026 and may change.