<a href="https://www.thenationalnews.com/business/money/billionaires-activist-investor-carl-icahn-considers-investing-1bn-in-cryptocurrencies-1.1235325" target="_blank">Corporate activist Carl Icahn</a>’s fortune tumbled more than $10 billion on Tuesday after <a href="https://www.thenationalnews.com/business/money/2023/01/26/what-is-gautam-adanis-net-worth-after-hindenburg-report/" target="_blank">short-seller Hindenburg Research </a>accused him of using a “ponzi-like” economic structure at his investment company. Icahn Enterprises, his publicly traded limited partnership that operates as a holding company, fell by 20 per cent — the most on record — erasing $3.1 billion from his fortune. Hindenburg also <a href="https://www.thenationalnews.com/business/billionaire-advisor-quits-white-house-role-in-further-blow-to-trump-1.620949" target="_blank">detailed Mr Icahn</a>’s margin loan collateralised by his stake in the company, which was not previously accounted for by the Bloomberg Billionaires Index. That lopped off another $7.3 billion from the net worth calculation. All told, Mr Icahn’s fortune sank by an unprecedented 41 per cent to $14.6 billion, according to the wealth index, dropping him from the world’s 58th-richest person to 119th. Mr Icahn, 87, is the latest billionaire to become the target of Hindenburg this year after the New York-based short-seller went after <a href="https://www.thenationalnews.com/business/2023/01/25/adani-shares-drop-after-hindenburg-report-accuses-indian-conglomerate-of-fraud/" target="_blank">India’s Gautam Adani </a>and <a href="https://www.thenationalnews.com/business/money/2023/03/24/jack-dorseys-wealth-falls-526m-after-hindenburg-shorts-block/" target="_blank">Block's Jack Dorsey</a>. Hindenburg’s attacks on the companies of Mr Adani and Mr Dorsey caused <a href="https://www.thenationalnews.com/business/money/2023/02/25/gautam-adanis-net-worth-slips-below-40-billion/" target="_blank">drops in their fortunes this year of $58 billion</a> and $500 million, respectively. The activist investor owns more than 85 per cent of Icahn Enterprises’ units through various entities, making up the bulk of his fortune. Hindenburg said the company, with investments in funds managed by Mr Icahn and controlling stakes in businesses in sectors such as energy, automotive and food, was overleveraged and traded at an extreme premium to its net asset value. Hindenburg also questioned how the company valued some of its investments. Mr Icahn called the report “self-serving” and “intended solely to generate profits on Hindenburg’s short position”. He has boosted his holding in Icahn Enterprises by taking dividends in the form of additional units. Before Tuesday’s decline, his stake was worth $15.7 billion, compared with $8.4 billion in 2017, even as the value of its shares declined by 4.9 per cent. Other unit holders received their dividends in cash, making the company attractive to retail investors, Hindenburg said. That was only possible because of Mr Icahn’s decision to take his payment in units, since the company was consistently operating with negative cash flows, the short-seller said. Mr Icahn began reporting a margin loan collateralised by his stake in the company in 2021, at a time when he had about 65 per cent of his shares pledged. He boosted the number last year and, as of February, had more than 181 million shares worth $9.2 billion backing the loan, according to the company’s 2022 annual report. Margin loans involve lending that is collateralised by the value of the underlying shares. If the value of the stock declines, lenders can request additional collateral or for the loan to be repaid, and have the ability to seize and sell the shares if a borrower fails to do so. Hindenburg criticised Mr Icahn for failing to disclose how much he had borrowed, the interest rate or the loan-to-value maintenance ratio associated with the margin loan. In its annual report, Icahn Enterprises said: “Mr Icahn has advised that he and his affiliates have sufficient additional assets to satisfy any obligations pursuant to these loans without recourse to the depository units, he has no need or intention to allow foreclosure on such collateral, and that he is current on all principal and interest payments with respect to the loans.” Mr Icahn’s second-largest asset is his stake in his investment funds, which he uses to make activist bets. Icahn Enterprises, Mr Icahn and his son, Brett, are the only investors in the funds. At the end of last year, Mr Icahn had $4.9 billion invested. Hindenburg calculated that the fund could be down about 17 per cent this year, based on an estimate of the performance of its long and short positions.