First, those who disagree with market efficiency simply assert that it stands to common sense that greater effort to get facts and greater acumen in analyzing those facts will pay off in better performance somehow measured. (By this logic, cure for cancer must have been found by 1955).
Paul SamuelsonStill, I figure we shouldn't' discourage fans of actively managed funds. With all their buying and selling, active investors ensure the market is reasonably efficient. That makes it possible for the rest of us to do the sensible thing, which is to index. Want to join me in this parasitic behavior? To build a well-diversified portfolio, you might stash 70 percent of your stock portfolio into a Wilshire 5000-index fund and the remaining 30 percent in an international-index fund.
Paul Samuelson