I don’t understand this “loop hole”, who is giving loans that don’t have to be repaid? Surely the collateral will be sold eventually to repay the loan and service the interest?
Refinance the loan with another loan or just use a revolving credit account with no fixed term.
If your stock holdings are growing faster than inflation and the interest rate at which you are borrowing, it’s an easy way to monetize unrealized gains without a taxable event. If you have a huge stock portfolio, brokers will lend you money against your stock at very low rates, a few bps above what Treasuries yield. If you have $4B of stock they might let you borrow $1B for what would be ~4-4.5% using that stock as collateral. You can theoretically take out a margin loan for up to 100% of the stock held in an account, but that’s risky due to margin calls.
The idea is to let the cost basis step up to the price of the asset at your death which will eliminate the capital gains that would’ve been owed. Then your heirs sell a portion of the stock to pay off the loan and keep the rest.
If you are a good customer of the bank and the LTV of the collateral is very low, then you will get a very low interest rate. If the collateral pays dividends (which are also taxed at a lower rate than ordinary income), then the dividends can service the interest. Meanwhile capital gains keep accumulating tax-free.