We must be cynics when reading the tape. I do not mean that we should be pessimists, because we must have open minds always, without preconceived opinions. An inveterate bull, or bear, cannot hope to trade successfully. The long-pull investor may never be anything but a bull, and, if he hangs on long enough, will probably come out all right. But a trader should be a cynic. Doubt all before you believe anything. Realize that you are playing the coldest, bitterest game in the world.
– Humphrey Neill, Tape Reading & Market Tactics