It’s tough to overstate the message such a move sends. It calls to mind a similar move Steve Ballmer made at Microsoft (MSFT) more than 25 years ago. Ballmer wasn’t a founder, but he owned a high-single-digit stake in the company. In 1989, three years after Microsoft went public, investors had lost faith in the software maker. The stock had fallen 27% in a month, and Ballmer, who held a similar role to the one Arora later had at Google, saw an opportunity. So he paid $46.2 million for 945,000 shares of additional stock.

It was a non-trivial amount of money for the then young executive. What’s more, as Ballmer revealed in an interview Friday, he borrowed the entire amount. “I bought that all on margin,” he said. “In a sense it’s a little scarier to borrow for it. I was 33. You borrow 40 million bucks. That felt like a big deal to me.” As for Arora’s more sizable number two and a half decades later: “That’s going to feel like a big deal to him.”

Looking back, Ballmer couches the investment as having been opportunistic, even though he understood the message he was sending. “I remember thinking I could make some real money on this. And I could make a real statement that I believed.” He says his only regret is that he closed out the margin debt sooner than necessary because he didn’t like the idea of borrowing money for too long.

Ballmer guesses that the investment represented about a quarter of his net worth at the time, and he praises Arora for committing what he assumes is a similarly large — or larger — relative commitment. “This is a big, bold thing for Nikesh to do,” Ballmer said. “He’s putting a big percentage of his net worth on the line.” Ballmer says he has sold Microsoft stock only seven or eight times, and his rationale for keeping his wealth in Microsoft stock was the unusual degree of control he had over the investment. He summarizes his wealth-management philosophy this way: “You can give your money to people to manage. You can buy index funds. Or you can put your money into the company you run, and then you know how you’re managing the money. This was my way of managing my own money.”

Ballmer’s public display of confidence in Microsoft got noticed, especially by existing and prospective employees. These included a future top executive, Brad Silverberg, whom Microsoft was wooing at the time. “Steve’s act said, ‘I really believe in this company and I’m putting my money where my mouth is,’” Silverberg recalled. “He was not superrich then, and it was a huge gamble and statement of confidence on his part. It had a huge impact on the company by showing how much Steve believed and was willing to put his financial life on the line.”

You’re probably wondering how Ballmer did on his bet. He bought the shares at a split-adjusted price of about 25 cents, compared with Microsoft’s closing price Friday of just over $43. That’s a return of 172 times his investment, making the original stake he purchased worth about $8 billion. He figures he held onto about two thirds of that. When Ballmer retired last year, just before buying the Los Angeles Clippers basketball team and years after Bill Gates had begun shifting his wealth to his foundation, Ballmer was the company’s largest shareholder.

A version of this post originally appeared in Data Sheet, Fortune’s daily tech-business newsletter. Click here to subscribe. For more on Softbank President Nikesh Arora, watch this video below.