NEW YORK (MarketWatch) — If Apple Inc.’s year had a theme, it was the year the company finally started to chip away at that colossal hoard of cash.

After a little nudging by activist investor Carl Icahn, Apple AAPL, +3.03% boosted its share-buyback program in April to $90 billion and increased the pace of capital returns. New data from FactSet show that Apple has been the biggest buyback spender of 2014 among the S&P 500, pouring more than $56 billion into the program on a trailing 12-month basis as of the end of the third quarter. That’s nearly three times the outlay of runner-up IBM Corp. IBM, -2.04% , which spent $19.2 billion.

Apple bought back $17 billion in shares last quarter, a 240% year-over-year increase that marks the second-highest dollar amount spent on buybacks during a quarter by any individual company in the S&P 500 since 2005, when FactSet began tracking the data. It’s second only to Apple’s own record of $18.6 billion set in the first quarter as part of the same buyback program.

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FactSet

Morningstar analyst Brian Colello said that while it’s not all surprising the world’s most valuable company would top a list such as this given its enormous cash cushion, he said the buybacks have undoubtedly been a “big contributor” to the stock’s strong performance in 2014.

Adjusted for a 7-for-1 stock split earlier this year, shares of Apple have climbed more than 43% over the last 12 months. Since hitting a 52-week low back on Jan. 30, they have been on the march higher — flirting with all-time highs since September.

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“It showed that management was confident in its upcoming product launches and helped to put a floor into the company’s valuation during times of skepticism,” said Colello.

Apple is the world’s most valuable company, with a $641.7 billion market cap, almost double the market valuations of the next companies on that list, Microsoft Corp. MSFT, +1.07% and Exxon Mobil Corp. XOM, -2.04% , both valued around $377 billion.

In total, the S&P 500 companies spent an aggregate $143.4 billion on share repurchases last quarter and $567.2 billion on a trailing 12-month basis. Those figures represent 16% and 27% respective increases from the same periods last year and put Apple’s contribution at 11.8% and 8.1%, respectively.

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Icahn’s insatiable appetite for returns, though, is rarely satisfied. The billionaire sent yet another letter to CEO Tim Cook in October saying the stock would be much higher if Apple spent a total of $100 billion on share repurchases. To provide perspective, that would represent 64% of Apple’s $155 billion in total cash, cash equivalents and marketable securities, as of its most recent 10Q filing.

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