Apple does not pay a dividend and does not repurchase any shares. The market cap of the company is greater than $300 billion. Exxon Mobil is the only company whose market cap exceeds Apple's. Exxon both repurchases shares and pays a dividend to help support the market cap. Apple's shareholders are left to do the heavy lifting on their own.
Not only does Apple not repurchase shares but they issue shares to employees through stock options. Apple's share count has increased by 15 million shares in the past year or $4.5 billion. Assuming this rate of share growth, the stock needs inflows of $4.5 billion a year just to keep the share price steady at current prices.
It has been easy to recruit new shareholders until now as Apple's popularity has grown wildly as has the share price. But the law of large numbers seems to be having an effect and if the stock stumbles it might make that job harder. The valuation and fundamentals of Apple seem solid but share price growth will be a challenge with management's current capital allocation strategy.