A low-cost index fund is the most sensible equity investment for the great majority of investors. My mentor, Ben Graham, took this position many years ago, and everything I have seen since convinces me of its truth.
Warren BuffettOur policy is to concentrate holdings. We try to avoid buying a little of this or that when we are only lukewarm about the business or its price. When we are convinced as to attractiveness, we believe in buying worthwhile amounts.
Warren Buffett