About 38.5 million shares of Apple as of 2013 or about 0.7%. That’s higher than the 0.5% owned by Steve Jobs at the time of his death simply because Apple has bought back many of their shares, lowering the volume and increasing the percentage owned.
While the stake in Apple is certainly valuable, the Laurene Powell Jobs Trust owns more than 7% of Disney and is the largest private shareholder of the company.