Apple Inc. (AAPL:UN), one of the most cash-rich companies in the world, is still looking to get a piece of the ultra-cheap money that’s up for grabs in the bond market.

With investment-grade bond yields hovering near record lows, it’s tempting even for Apple -- with more than US$200 billion of cash and investment securities on its books -- to see what investors will lend it. Turns out that number is US$7 billion, or just over three per cent of its current coffers.

With the 30-year Treasury at record lows, many companies have been able to borrow more cheaply for much longer. Apple will pay around 2.99 per cent interest on its new 30-year bonds, compared with the 3.45 per cent it’s paying on three-decade bonds it sold in 2015. On a US$1.5 billion issue, that equates to savings of nearly US$7 million of interest annually, or more than US$200 million over the course of three decades.

Today’s debt sale could help Apple refinance roughly US$2 billion of debt that’s scheduled to mature this year in addition to much of the US$10 billion it has coming due in 2020, according to data compiled by Bloomberg. The borrowing is profitable for the company’s shareholders by at least one measure: the company’s earnings yield, a measure of how much the company earns relative to its share price, is around 5.6 per cent, while it can borrow for 30 years for less than three per cent.

Apple’s not the only one seizing this golden opportunity. A record 21 U.S. investment-grade companies tapped the market Tuesday, borrowing a combined US$27 billion. With more than a dozen deals in the works Wednesday, this week’s issuance is already set to hit US$54 billion, comfortably surpassing dealer estimates of US$40 billion.