The largest Apple shareholders are all large mutual funds, a number of them index funds that hold a large number shares to match their investment prospectus of having an asset portfolio that matches the distribution of a certain market segment.
These large mutual funds don't care if Apple's share price is $542 or $54.20. They have sufficient funds to purchase the Apple shares they want to/have to. And most of them do not buy and sell for the short-term to make profits now, they are investing for the long-term.
Investing in mutual funds is actually the best way for most smaller investors to benefit from Apple's success while protecting against risk. Lower fees than buying and selling shares individually, and not all your eggs in one basket.
I do not directly own Apple stock, but I benefit from stock price increases and any dividends Apple might pay because I own some of those mutual funds.
Here are the largest Apple shareholders, and the number of shares they own. If you want to invest in Apple, consider one of them.
Fidelity Contrafund - 11,920,058
Vanguard Total Stock Mkt Idx - 11,363,899
Vanguard 500 Index Inv - 8,606,953
Vanguard Institutional Index - 8,474,805
PowerShares QQQ - 9,529,080
SPDR S&P 500 - 9,341,170
T. Rowe Price Growth Stock - 5,586,900
Fidelity Growth Company - 6,090,959
American Funds Growth Fund of Amer A - 5,022,500
CREF Stock - 4,635,248
Vanguard Growth Index Inv - 3,616,717
Fidelity Spartan 500 Index Inv - 3,551,079
Fidelity Advisor New Insights A - 2,853,079
T. Rowe Price Blue Chip Growth - 2,452,000
Technology Select Sector SPDR - 2,749,875
Fidelity Blue Chip Growth - 2,384,100
Harbor Capital Appreciation Instl - 2,005,258
Wells Fargo S&P 500 Index Fund F - 1,918,562
Janus Twenty D - 1,844,354
iShares Russell 1000 Growth Index - 2,232,465