“Which is worse, buying at the top or selling at the bottom? For me the answer is easy: the latter. If you buy at what turns out to have been a market top, you’ll suffer a downward fluctuation. But that isn’t cause for concern if the long-term thesis remains intact. And anyway, the enxt top is usually higher than the last top, meaning you’re likely to be ahead eventually. But if you sell at a market bottom, you render the downward fluctuation permanent, and, even more importantly, you get off the escalator of a rising economy and rising markets that has made so many long-term investors rich. This is why I describe selling at the bottom as the cardinal sin in investing.” – Howard Marks