Chart of the day: Apple tops the favorite stocks of 21 billionaires by Philip Elmer-DeWitt @FortuneMagazine February 19, 2014, 9:11 PM EST E-mail Tweet Facebook Google Plus Linkedin Share icons Source: iBillionaire. Click to enlarge. FORTUNE — There are a million ways to try to beat the market, and the one iBillionaire has chosen is as good as any, I suppose. What started as an iOS app (iBillionaire) and website (iBillionaire.me) morphed at the end of October into an exchange-traded fund (ETF) that offers investors a portfolio of 30 stocks selected to mirror the investment strategies of 21 billionaire investors — people like Warren Buffett, George Soros and Carl Icahn. Here’s the iBillionaire pitch: “We analyze more than 250 billion dollars in assets held and managed by a pool of over 20 billionaires. Each quarter, we look at roughly 1,500 investments, 93% in equities and 7% belonging to other asset classes. Our software has processed over a decade of SEC filings to ensure that the iBillionaire Index is a diversified portfolio of high-quality companies. “ Source: iBillionaire The goal is simple: Beat the S&P 500. And how’s that working? So far so good. Since Oct. 31, the iBillionaire fund is up 7.3% compared with 4.8% for the S&P 500. The catch, I suppose, is that when events unfold quickly iBillionaire will always be a beat behind the real billionaires. Below: The top 10 stocks in the index and their relative share in the S&P 500. Note that in both cases, Apple AAPL is the No. 1 security, although it is weighted more than three times as heavily in the iBillionaire fund than in the broader index.