Apple has $115 billion of debt outstanding, and it has distributed $288 billion to its shareholders in the past six years, most of it through share buybacks. In the most recent nine months alone, Apple bought back $54 billion worth of shares.

This transformation is representative of trends in corporate America. According to the Federal Reserve, corporations have issued on net over $1.3 trillion of debt and retired over $1.9 trillion of equity over the past four years. American companies are borrowing money to buy their own shares in what is tantamount to a huge, slow-motion leveraged buyout.

Apple has conducted its buybacks responsibly: It bought shares when they were relatively cheap, rewarding the patient shareholder. Other companies have not been so prudent, taking on debt to make ill-timed purchases of expensive shares rather than investing in growth opportunities. In some cases, they have done so simply to push up share prices so that management can meet goals for quarterly earnings or metrics that trigger compensation.

Second, Apple’s financial model emphasizes cash flow over profits. Apple is not simply immensely profitable; in 2017, it generated $16 billion more in operating cash flow than profits. It does that in part by running its day-to-day operations in a distinctive way. Typically, a company has to use external funds to fund the process of stocking goods and collecting revenue from customers.

Apple’s model turns this upside down. Its retail stores collect cash from customers quickly, it is ruthless on keeping inventory low, and it takes forever to pay suppliers. In the process, Apple’s operations are extremely effective cash generators. This is no coincidence. It is the result of the canny supply chain that Tim Cook built. In effect, Apple has largely been financed on the backs of its suppliers, who are willing to hold their inventory and wait more than 100 days to get paid, just for the pleasure of doing business with Apple.