Billionaire Larry Ellison lost almost $200 billion in a year.

American billionaire Larry Ellison stands behind two of the biggest borrowers in corporate America, and bond investors have started to treat them as one bet.

Paramount Skydance completed a $52 billion financing package on Wednesday to fund its $111 billion takeover of Warner Bros. Discovery, the deal led by Ellison's son David. Oracle, the software company Ellison co-founded and still owns about 40% of, has nearly doubled its long-term debt to more than $160 billion in two years to build data centers for artificial intelligence, making it the fifth-largest borrower in the U.S. corporate bond market.

The link between them is Ellison himself: a family trust guaranteed a large share of the roughly $47 billion of equity in the Paramount deal, and the family pledged to credit agencies that it would take whatever steps were needed to bring Paramount's leverage down, a commitment the market read as a promise to put in more money if required.

The worry, Bloomberg reported on Saturday, is what that promise is worth if Oracle's stock keeps falling. "You have to consider your total Larry Ellison risk," said Campe Goodman, a portfolio manager at Wellington Management, who argues investors should treat Oracle and Paramount as related credits. The cost of insuring each company's debt against default has converged and now moves in step.

Ellison's net worth tells the story. A year ago Oracle's shares hit a record on AI optimism and briefly made him the world's richest person. Since then his fortune has dropped by almost $200 billion, more than anyone else on the planet, according to the Bloomberg Billionaires Index, which now puts him at about $192 billion, still inside the top 10.

Oracle's shares have fallen more than 50% over 12 months as heavy capital spending pushed free cash flow deeply negative; S&P cut the company to BBB-, its lowest investment-grade rating, in July. Last month Ellison cancelled a plan to sell billions of dollars of Oracle stock and disclosed that he had increased the number of shares pledged as collateral for personal loans.

Paramount's new debt consists of $30 billion of investment-grade bonds, $12.4 billion-equivalent of junk bonds and $9.46 billion of loans. S&P rates the company BB, two notches into junk, on the leverage the Warner Bros. acquisition brings. In the run-up to the sale, investors were openly debating how much weight to give the Ellison family's pledge, market participants told Bloomberg. "Part of the Paramount credit story is tied to confidence in the Oracle story, because Larry Ellison's financial strength sits behind both," said Steven Schweitzer of Advent Capital Management.

S&P's analyst Jawad Hussain put the mechanism plainly: if Paramount underperforms and Oracle's stock falls at the same time, "you still have the same asset base," and the question becomes whether the Ellisons can still support a business that needs to deleverage. Brett Kozlowski of GW&K noted the risk runs both ways: a stumbling merger could pull Oracle's balance sheet toward Paramount's problems, to the benefit of Paramount bondholders and the cost of Oracle's.

Paramount and Oracle did not respond to requests for comment, and attempts to reach Ellison through his foundation went unanswered.

The deal itself has cleared its hurdles. Paramount settled with 12 state attorneys general, a federal judge heard the consent decree last month, and the merger was expected to close within weeks. What remains is execution: combining two studios, two streaming services and two news networks while servicing debt that the ratings agencies already consider heavy, in a group whose ultimate backstop is a single shareholder's position in a single volatile stock.

Ellison has been here before. He borrowed against Oracle shares to buy an island, a sailing team and most of a Florida coastline, and the loans never came due at the wrong moment. This time the bet is not a yacht. It is the largest media company in America, financed on the assumption that the Oracle rally has further to run.