The "Buy Borrow Die" you mentioned is a legal tax planning method commonly used by wealthy Americans. It is not a specific legal provision, but a combination of financial management and inheritance strategy. The principle is roughly as follows: ⸻ 1. Buy Rich people purchase high growth assets (stocks, large real estate, company equity, encrypted assets, etc.) and hold them for the long term. In the United States, there is no capital gains tax on unsold assets. Rich people usually choose assets that can appreciate in the long term and have collateral value. ⸻ 2. Borrow After asset appreciation, do not sell, but use mortgage loans to cash out: For example, Securities Based Lending (SBL) and real estate mortgage loans. Borrowed cash can be used for consumption, reinvestment, or charitable purposes. Loans are not considered income → no income tax is required. Interest can often be offset against taxes (especially for real estate related loans). ⸻ 3. Die When a wealthy person passes away, the heir benefits from the "Step up in Basis" rule (cost base adjustment): When the heir acquires assets, the cost basis is reset to the market value on the day of death. This means that the accumulated appreciation over the past few decades has been cleared of capital gains tax. Loans can be repaid with assets from the estate, while the remaining assets are passed on "cleanly" to the next generation. ⸻ Let me give you a simple example A wealthy man bought Apple stock worth $1 million 30 years ago, and now has a market value of $100 million. If sold, a capital gains tax of 20% or more is required, which may cost over 20 million yuan in taxes. He chose not to sell, but instead borrowed 30 million yuan with stock collateral to continue living and investing. At the time of death, the heir received stocks, and the cost base was "refreshed" to 100 million. If the heir sells immediately, there is almost no need to pay capital gains tax. ⸻ 4. Key benefits Delayed tax payment (or even exemption). Maintain the compound interest effect of asset growth. Realize intergenerational wealth inheritance. ⸻ 5. Risks and Limitations If Congress modifies the tax law (such as canceling Step up in Basis), the strategy may become ineffective. Excessive borrowing and asset price decline may force liquidation. Requires good liquidity and professional wealth management. ⸻ Summary: The 'buy borrow die' strategy is not a loophole, but rather a combination of deferred capital gains, mortgage exemption, and step-by-step approach in the US tax code. Ordinary people can also use similar logic (such as holding a property for a long time and using a mortgage to cash out), but the effect is more pronounced on the wealthy.