While Warren Buffett ended his time as CEO of Berkshire Hathaway putting up a tremendous track record identifying individual companies to buy, his advice for the majority of investors is quite simple. He suggests buying an index fund that tracks the performance of the S&P 500. The Vanguard S&P 500 ETF (NYSEMKT: VOO) is a top choice. Before you add this exchange-traded fund (ETF) to your portfolio, here are three things you must know. Where to invest $1,000 right now? Our analyst team just revealed what they ...