What Is a Portfolio Line of Credit: Costs, Risks, and Tax Rules

A portfolio line of credit is a revolving credit facility secured by the stocks, bonds, and funds in your taxable brokerage account, letting you borrow against those holdings without selling them. You typically get access to somewhere between 50% and 95% of your eligible portfolio’s value, pay interest only on what you draw, and keep receiving the dividends and interest your investments generate. The appeal is real, especially for investors with large unrealized gains, but so are the risks: variable rates, tight tax rules on interest deductibility, and margin calls that can force your positions to be sold at the worst possible moment.

How It Works

Also called a securities-backed line of credit, or SBLOC, a portfolio line of credit gives you a maximum borrowing limit based on the value and composition of a pledged brokerage account. Draw any amount up to that limit, repay it, draw again. Interest accrues only on the outstanding balance.

You can use the funds for almost anything: a tax bill, a business, a vacation home, a bridge between illiquid transactions. The one hard restriction is that the proceeds cannot be used to buy or carry securities. Federal Reserve Regulation U treats a loan against your investments for non-securities purposes as “non-purpose credit,” and that classification is what lets lenders offer higher advance rates and looser terms than they can on a traditional margin account.1eCFR. 12 CFR Part 221 – Credit by Banks and Persons Other Than Brokers and Dealers (Regulation U)

You retain ownership of the pledged securities the whole time. Dividends and interest still flow to you, and most lenders let you continue trading within the account, though shifts in composition can change how much you’re allowed to borrow.

What You Can Pledge

Lenders evaluate two things about your holdings: how quickly they can be sold, and how predictable their prices are. The more liquid and stable, the higher the advance rate.

  • U.S. Treasury securities and investment-grade bonds get the highest advance rates, often 85% to 95% of market value.
  • Large-cap stocks and diversified equity ETFs typically qualify at 50% to 70%.
  • Widely held, liquid mutual funds generally qualify, with rates depending on the underlying holdings.
  • Concentrated single-stock positions receive significantly lower advance rates or may be excluded entirely.

Wells Fargo, as an example, advertises the ability to borrow between 50% and 95% of eligible asset value depending on collateral type.2Wells Fargo Advisors. Securities-Based Borrowing Your actual limit depends on the mix, not any single position.

What You Cannot Pledge

Retirement accounts are off-limits. Pledging any portion of an IRA as collateral for a loan causes the IRS to treat the pledged amount as a distribution, triggering income tax and potentially early-withdrawal penalties.3Office of the Law Revision Counsel. 26 U.S. Code 408 – Individual Retirement Accounts For 401(k) and other qualified plans, using plan assets as security is a prohibited transaction that can disqualify the plan and generate excise taxes.4Office of the Law Revision Counsel. 26 USC 4975 – Tax on Prohibited Transactions Private equity, direct real estate, and restricted stock don’t qualify either, since lenders need collateral they can price and sell on short notice. Only fully paid-for securities in a taxable brokerage account are eligible.

What It Costs

Rates are almost always variable, calculated as a benchmark plus a fixed spread. Most lenders now reference the Secured Overnight Financing Rate (SOFR), though some still use prime.

Larger balances get better spreads. Schwab’s Pledged Asset Line as of March 2026 charges SOFR plus 4.40% for lines between $100,000 and $250,000, dropping to SOFR plus 2.40% for lines of $2.5 million or more. APRs work out to roughly 6% to 8%, with additional discounts tied to household assets at the firm.5Schwab Bank. Pledged Asset Line Rates

Those numbers usually beat unsecured personal loans or credit cards, but they float. If SOFR rises, your monthly interest cost rises with it, even if you never draw another dollar. Over a multi-year borrowing period, rate moves can materially change the math.

Fees are where PLOCs look genuinely cheap. Most lenders charge no application fees, origination fees, annual maintenance charges, or prepayment penalties.6Huntington Bank. Understanding a Securities-Backed Line of Credit Interest on the outstanding balance is essentially the only cost. Many agreements require only interest payments for a set term of three to five years, with principal due as a balloon at the end. Others renew automatically after a collateral and financial review.

Tax Rules to Understand Before You Draw

The tax treatment is one of the main reasons wealthy investors use these lines, but the rules are more precise than most summaries suggest.

Borrowing Doesn’t Trigger Capital Gains

Selling appreciated stock realizes a capital gain. Borrowing against that same stock doesn’t.7FINRA. Securities-Backed Lines of Credit Explained For an investor with $2 million in stock and a $400,000 cost basis, the difference between selling and borrowing can easily be six figures in avoided tax.

Interest Deductibility Follows the Use of the Money

Whether you can deduct the interest has nothing to do with the collateral and everything to do with what you spent the borrowed funds on. Under the IRS’s interest tracing rules, deductibility follows the use of the loan proceeds, not the source of security. The regulation gives an explicit example: if you pledge investment stock but use the loan to buy a car, the interest is personal interest and is not deductible.8eCFR. 26 CFR 1.163-8T – Allocation of Interest Expense Among Expenditures

Use the proceeds for investment purposes and the interest qualifies as investment interest, deductible up to your net investment income for the year, with any excess carrying forward.9Office of the Law Revision Counsel. 26 U.S. Code 163 – Interest Use it for a business and it’s generally a business expense. Use it for personal spending, like a home purchase or living expenses, and it’s non-deductible under current law. Commingling the proceeds in an account you also use for other purposes makes the tracing hard to defend at tax time, so keeping separate accounts for separate uses is the practical answer.

Buy, Borrow, Die

At the high end, some investors use portfolio lines of credit as part of a long-term wealth transfer plan. Buy appreciating assets, borrow against them instead of selling, and hold until death. Heirs then inherit with a stepped-up basis equal to fair market value at the date of death, which eliminates the built-in capital gain.10Office of the Law Revision Counsel. 26 U.S. Code 1014 – Basis of Property Acquired From a Decedent The heirs sell tax-free (or close to it) and use the proceeds to repay the loan. A lifetime of appreciation escapes income tax altogether.

The strategy works under current law, has drawn reform proposals, and isn’t free: interest still accrues and margin-call risk still exists throughout the borrower’s life.

Margin Calls Are the Real Risk

This is where portfolio lines of credit turn dangerous, and where most borrowers underestimate what they’ve signed up for. The lender monitors the market value of your pledged securities continuously. If the account drops below a required threshold relative to your outstanding balance, you get a margin call demanding that you restore the ratio. You can deposit cash, pledge more eligible securities, or pay the loan down. The timeline is short and the lender sets it.

The part that catches people off guard: lenders don’t have to warn you first. FINRA’s rules allow firms to liquidate securities at their discretion to eliminate a margin deficiency.11FINRA. Margin Regulation Merrill’s margin handbook puts it plainly: they will try to notify you, but they don’t have to, and even if they give you a deadline, they can still sell your holdings immediately if they decide it protects their position.12Merrill Edge. Merrill Edge Margin Handbook You don’t get to choose which positions they sell.

Forced liquidation during a downturn is the worst case. It locks in losses at the low, can trigger a large capital gains bill on low-basis positions, and shrinks the collateral that supports the remaining loan. The practical defense is not to borrow near your limit. If your line is $500,000, running a balance around $300,000 or less leaves the portfolio room to absorb a real decline before a call is triggered.

Other Risks Worth Knowing

  • Variable rate exposure. A loan costing 6% today can cost 9% in two years if rates climb, with no cap.
  • Locked collateral. Once pledged, you generally need the lender’s permission to withdraw assets, transfer the account, or in some cases even sweep out dividends. Closing the line means paying it off first.
  • Shifting borrowing capacity. Trading toward riskier or less liquid holdings can cause the lender to reduce your limit. A bond downgrade or a stock falling below a price threshold can do the same, potentially triggering a margin call with no change in the broader market.
  • Renewal discretion. At the end of a three- to five-year term, the lender reviews your collateral and finances and can decline to extend, widen the spread, or cut the limit.
  • Death of the borrower. Most agreements accelerate the loan at death, making the full balance due immediately. The estate has to repay it, which can force the very sale the borrower was avoiding unless heirs can refinance or pledge their own assets.

How It Compares to Alternatives

  • Margin loan. Also secured by your brokerage account, but structured for buying securities. Under the purpose-credit rules, advance rates on stocks are capped at 50%. A PLOC, as non-purpose credit, can go higher.
  • HELOC. Secured by your home rather than your investments, often at comparable rates. Interest may be deductible when used for home improvements, but the collateral is your house. A PLOC swaps that risk for portfolio risk, and approval is usually faster because there’s no appraisal.
  • Unsecured personal loan. No pledge required, but rates are much higher and limits are lower. Fits smaller needs where you’d rather not tie up assets.
  • Selling the investments. Simplest option, but it realizes capital gains and permanently removes the assets from your portfolio. For a low-basis position, the tax cost of selling can outweigh several years of interest on a loan.

Applying

Because the loan is fully collateralized, underwriting focuses on the securities more than on you. Some lenders, like Wealthfront, skip the credit check entirely.13Wealthfront Support. Is There a Credit Check Needed to Open a Portfolio Line of Credit? Others pull credit and review income documentation, especially for larger lines. The main requirements:

  • Minimum portfolio size. Most lenders start at $100,000 in eligible securities. Fidelity sets a $100,000 minimum line and typically expects at least $500,000 pledged. Schwab’s minimum is $100,000.14Fidelity. Securities Backed Line of Credit5Schwab Bank. Pledged Asset Line Rates
  • Eligible account type. A taxable brokerage account with fully paid-for securities. No retirement accounts, no already-pledged securities, no restricted stock.
  • Recent brokerage statements. The lender analyzes composition, diversification, and liquidity to set the advance rate and maintenance requirement.
  • Financial statements. For larger lines, expect to show assets, liabilities, and income to demonstrate you can service the interest.

Timelines have shortened. Fidelity advertises access to funds within a few business days of approval.14Fidelity. Securities Backed Line of Credit Concentrated positions, multiple accounts, or very large lines can take longer. Once funded, the approved amount usually sits in a linked checking or money market account you can draw against without reapplying.

When sizing your draw, resist the urge to max out. The space between your outstanding balance and your credit limit is the buffer that protects you from a margin call. Borrowing 40% to 60% of the approved amount gives most portfolios room to absorb a meaningful correction before anything gets sold on your behalf.