The Loan Architecture

The strategy is called Buy-Borrow-Die. The name was coined by Edward McCaffery, a tax law professor at the University of Southern California, in the mid-1990s to describe the three-step architecture through which holders of large appreciated asset positions convert wealth into functional income without triggering income tax. The strategy exploits two structural features of the U.S. tax code: unrealized appreciation is not income, and borrowed money is not income. Together, these features create a channel through which virtually unlimited purchasing power can be accessed from an appreciating asset base without a taxable event ever occurring.

Step one is accumulation. A founder, executive, or investor acquires a large equity position — typically stock in a company they founded or led — and holds it. The position appreciates, often by billions of dollars. No tax is owed because no sale has occurred. Under the realization principle that has governed American income taxation since Eisner v. Macomber (1920), appreciation in asset value is not income until the asset is sold or exchanged. A person whose net worth increases by $10 billion in a year through stock appreciation has not, for tax purposes, received $10 billion in income. They have received nothing.

Step two is borrowing. Rather than selling the appreciated stock and triggering capital gains tax, the holder pledges the stock as collateral and borrows against it. Banks extend securities-backed lines of credit at favorable rates — historically, spreads of 1 to 3 percentage points above benchmark rates like SOFR for the largest borrowers. The cash received from the loan is not income. It is debt. The holder now has functional spending power equivalent to a sale, but has triggered no tax liability. For holders with sufficiently large and liquid positions, the borrowing capacity is effectively unlimited: banks will lend 50 to 70 percent of the pledged portfolio value, and the portfolio continues to appreciate even while pledged.

Step three is death. When the holder dies, their heirs receive the appreciated stock at its fair market value on the date of death — the stepped-up basis provision of IRC Section 1014. The embedded capital gains that accumulated over the holder's lifetime are eliminated. The heirs can sell the stock immediately at the stepped-up basis and owe no capital gains tax on any of the appreciation that occurred during the original holder's life. The proceeds from the sale retire the outstanding loans. The wealth has been accessed, spent, and transferred without capital gains tax ever being paid on the original appreciation.

In June 2021, ProPublica published "The Secret IRS Files," based on a trove of tax return data covering thousands of the wealthiest Americans over more than fifteen years. The investigation introduced a metric the outlet called the "true tax rate" — the percentage of federal income tax paid relative to the increase in wealth (as estimated by Forbes) over the same period. By this measure, the results were striking. The 25 wealthiest Americans saw their collective wealth increase by $401 billion from 2014 to 2018. They paid $13.6 billion in federal income tax over that period — a true tax rate of 3.4 percent.

The individual figures were more granular. Warren Buffett, whose wealth grew by approximately $24.3 billion over the 2014–2018 period, reported $23.7 million in total federal income tax — a true tax rate of roughly 0.1 percent. Jeff Bezos, whose wealth increased by $99 billion over the same window, paid $973 million in tax — approximately 0.98 percent. Bezos paid no federal income tax in 2007 and again in 2011. Elon Musk paid no federal income tax in 2018. Michael Bloomberg paid a true tax rate of 1.3 percent. These figures are not allegations of evasion. Every return was filed in full compliance with the law. The low rates are the product of the architecture: wealth held as unrealized appreciation is not income, and money accessed through borrowing is not income.

ProPublica's methodology was contested by some economists who argued that comparing taxes paid to wealth growth is misleading because the tax code taxes realized income, not wealth. This objection is technically correct and substantively confirms the paper's thesis: the code is designed to tax income, and the Buy-Borrow-Die architecture is designed to ensure that wealth is never converted into income. The objection and the strategy are the same observation stated from different directions.

A subsequent White House analysis by economists Greg Leiserson and Danny Yagan, published in September 2021, estimated that the top 400 wealthiest American families paid an average federal individual income tax rate of 8.2 percent from 2010 to 2018 — lower than the rate paid by most working households. The finding used a broader income concept that included unrealized capital gains, consistent with economic definitions of income but not with the tax code's definition. The gap between these two definitions is the architecture's operating space.

The stepped-up basis is the mechanism that closes the loop. Under IRC Section 1014, property acquired from a decedent receives a basis equal to its fair market value at the date of death. If a founder purchased stock for $1 million that appreciated to $10 billion over a lifetime, and the founder dies without ever selling, the heirs receive the stock with a basis of $10 billion. The $9.999 billion in appreciation is never taxed as capital gains. It is eliminated from the tax system entirely.

The Joint Committee on Taxation estimated that the stepped-up basis provision will account for approximately $58 billion in forgone federal revenue in 2024 — roughly one quarter of all revenue from capital gains taxation. The Congressional Budget Office found that in 2019, 56 percent of the provision's benefits accrued to the top 20 percent of decedents' estates, with $7 billion flowing to the top 1 percent alone. Eliminating the stepped-up basis would raise an estimated $230 billion over ten years if heirs instead inherited the original cost basis, or $570 billion if gains were taxed at death.

The provision's original rationale was administrative: without stepped-up basis, heirs would need to determine the original purchase price of inherited assets, which could be decades old and poorly documented. This rationale was plausible in 1921, when the provision was codified. It is considerably less persuasive in an era of electronic brokerage records and automated cost-basis tracking. The provision persists not because of its administrative justification but because of its distributional consequence: it is the single largest tax benefit accruing to holders of appreciated assets, and its beneficiaries are concentrated among the wealthiest estates — precisely the constituency with the resources to defend it politically.

The interaction between borrowing and stepped-up basis is the architecture's most consequential feature. Without stepped-up basis, Buy-Borrow-Die becomes Buy-Borrow-Pay: heirs would inherit the original low basis, and selling stock to repay loans would trigger capital gains tax on the full appreciation. Stepped-up basis converts a deferral strategy into an elimination strategy. The tax is not postponed. It is cancelled.

The strategy's economics depend on a rate comparison. The long-term capital gains tax rate for the highest earners is 20 percent, plus a 3.8 percent net investment income tax — 23.8 percent total. Selling $1 billion of appreciated stock with a near-zero basis would generate approximately $238 million in tax. Borrowing $1 billion against the same stock, at a securities-backed lending rate that has historically ranged from 2 to 6 percent depending on the benchmark rate environment, generates annual interest costs of $20 to $60 million — a fraction of the tax that a sale would trigger. Over a decade, the cumulative interest payments on the loan remain well below the one-time tax cost of selling.

The comparison is even more favorable when the underlying asset continues to appreciate. A holder who borrows $1 billion against a $3 billion stock position and the position grows to $5 billion has increased their borrowing capacity by $2 billion while paying only interest on the original loan. The asset base grows faster than the debt service costs, creating a compounding advantage. The larger the position and the higher the appreciation rate, the more favorable the economics of borrowing over selling become. This is why the strategy is disproportionately available to — and disproportionately beneficial for — the very wealthiest holders.

The scale of securities-backed lending reflects the strategy's prevalence. According to SEC filings and financial analyst estimates, Elon Musk has pledged over $90 billion worth of Tesla shares as collateral for personal borrowing — the largest stock-backed debt position of any corporate executive. Larry Ellison, Oracle's co-founder, has pledged approximately 346 million Oracle shares, worth over $100 billion, to secure personal term loans. These are not exotic arrangements. They are standard products offered by every major private bank and wealth management division. The securities-backed line of credit market exceeded $138 billion in outstanding balances as of early 2024, with the borrowing overwhelmingly concentrated among high-net-worth and ultra-high-net-worth individuals.

The Buy-Borrow-Die architecture is not a loophole. It is the interaction of three deliberate features of the tax code — realization-based income taxation, the non-taxation of borrowed funds, and the stepped-up basis at death — operating exactly as designed. No fraud is required. No aggressive interpretation of ambiguous law is necessary. The strategy is taught in every major tax law program, recommended by every sophisticated wealth advisor, and implemented by every private bank. Its existence is fully documented in academic literature, congressional testimony, and IRS data. Its continued operation requires only that Congress not change any of the three features on which it depends.

The distributional consequence is a tax system that is formally progressive — higher incomes face higher marginal rates — but functionally regressive at the very top. A wage earner making $500,000 per year pays an effective federal rate of approximately 30 percent. A billionaire whose wealth increases by $5 billion in the same year, who borrows against the appreciation and realizes no income, pays an effective rate approaching zero. The tax system's progressivity applies to income. The architecture ensures that the largest accumulations of economic advantage are never classified as income.

Reform efforts have been persistent and unsuccessful. President Biden's fiscal year 2023 budget proposed taxing unrealized capital gains for taxpayers with more than $100 million in wealth — a direct response to the Buy-Borrow-Die architecture. The proposal did not advance in Congress. President Obama proposed eliminating stepped-up basis in 2015; the proposal was abandoned within months. The political economy of the architecture favors preservation: its beneficiaries are concentrated, wealthy, and politically engaged; its costs are diffuse, invisible, and borne by the general public through higher taxes on earned income or reduced public services.

The Loan Architecture is the Corporate Shell's second layer. Where the Delaware Design provides the governance container that minimizes accountability, the Loan Architecture provides the income conversion mechanism that minimizes taxation. The holder accumulates wealth inside the container, borrows against it rather than realizing it, and passes it to heirs at stepped-up basis. The system works as designed. The design is the problem.