Over the past five years, Apple's (NASDAQ:AAPL) market capitalization has risen by a nice 79%. But its stock has soared 137% over this same timeframe. What gives?

Investors can thank the company's aggressive repurchases of its shares for the outsize gain in Apple's stock price. The tech giant has been an excellent steward of its excess capital, buying back shares opportunistically -- and fiscal 2019 was no exception. Apple bought back over $67 billion worth of shares during the year.

Here's a closer look at how Apple is deploying its excess cash to increase shareholder value.

A pile of cash

Image source: Getty Images.

Apple's aggressive repurchase program

Apple has had a cash problem for a while now. A good cash problem, that is. By the end of the company's third quarter of fiscal 2012, the tech giant had accumulated $117.2 billion of cash -- and that figure was growing rapidly. 

To put this capital to work, Apple's board of directors announced a dividend and a share repurchase program in March of 2012. Since then, Apple has paid a meaningful, growing dividend and has been repurchasing shares in droves, with the tech company buying back $67.1 billion of its own stock in fiscal 2019 alone.

The most recent update to Apple's capital return program was earlier this year.

"Given our confidence in Apple's future and the value we see in our stock, our Board has authorized an additional $75 billion for share repurchases," said Apple CFO Luca Maestri in the company's April 30 quarterly update. "We are also raising our quarterly dividend for the seventh time in less than seven years."

The impact of Apple's share repurchases on its share count has been significant. Over the past five years, total shares have been reduced by a whopping 24%. Zooming out to when the share repurchase authorization began in 2012, total shares outstanding have decreased by more than 32%.

There's more where that came from

More share repurchases are probably on the way.

Apple's recent $75 billion increase to its authorization put the total current authorization at $175 billion. As of Sept. 28, 2019, $96.1 billion of this authorization had already been utilized. But this leaves $78.1 billion yet to be spent.

Given Apple stock's relatively conservative valuation and the precedent management has set by exhausting all previous repurchase authorizations, Apple will likely continue to repurchase more shares in the coming quarters. After all, Apple has significant cash to deploy. As of the end of Apple's most recent quarter, the company had $98 billion of net cash. Even more, the tech giant is generating close to $60 billion of annual free cash flow.