Now we have some clues as to how Ellison funds his acquisitive lifestyle.
According to Oracle’s proxy, filed this month, Ellison has pledged 139 million shares “as collateral to secure certain personal indebtedness, including various lines of credit.” In other words, he’s got over $4.2 billion worth of stock pledged for personal loans.
That may seem like a drop in the bucket, since he’s still got 1.144 billion shares. The pledged stock represents only 12 percent of his share holdings.
Still, Ellison’s stock-backed borrowing has grown dramatically. Last year, he pledged 40 million shares. So the number of shares he’s using for personal loans and lines of credit have more than tripled over the past year. (Read more: Ultra Rich Spend Less on Bling)
One big reason may be Lanai. This summer, Ellison made news when he purchased the island, Hawaii’s sixth largest, for a reported $500 million.
His serial real-estate buying has continued: this week Ellison reportedly picked up another home in Malibu, where he already has at least five other properties.
His trophy collection now includes a former Astor family mansion in Rhode Island, a 10,742-foot home in San Francisco, a historic garden property in Kyoto, three parcels in Lake Tahoe, and Porcupine Creek, a 240-acre estate in California once owned by the billionaire couple Tim and Edra Blixseth, with its own 19-hole golf course.
Ellison also just took delivery of a new yacht, and has spent tens of millions on acquiring the BNP Paribas Open tennis tournament and sponsoring boats in the America’s Cup sailing race.
An Oracle spokeswoman declined to comment on Ellison's borrowing or spending.
Ellison, of course, is free to spend what he likes on what he likes. He’s that rarest of entrepreneurs who have created and built a company valued at over $100 billion. His company and his spending have both created countless jobs. He's also pledged to give away at least half of his wealth to charity. (Read more: Did the Forbes 400 Really 'Build That'?)
Yet the sudden increase in Ellison's debt fits the pattern of today’s High-Beta Rich: large leverage, large spending, and a high concentration of net worth in a volatile stock. Shareholders might want to take note of how many shares listed under Ellison are actually pledged to a lender.
The large pledge this year has even prompted Bloomberg to cut Ellison’s reported net worth by $3.5 billion, dropping him to No. 8 on Bloomberg’s global Billionaires Index. (His net worth is listed at $36.4 billion; Forbes pegged him at $41 billion on its latest list).
It's also worth remembering what Ellison’s own financial adviser told him in 2002. According to emails that emerged in court documents, accountant Philip Simon told Ellison that the $194 million Ellison had spent on his yacht, $25 million spent on a villa in Japan and $20 million for “lifestyle” was starting to add up.
“I’m worried Larry,” he wrote. “We have a freight train going down a track, hitting a debt wall.”
-By CNBC's Robert Frank
Follow Robert Frank on Twitter: @robtfrank