"Observation, experience, memory and mathematics—these are what the successful trader must depend on. He must not only observe accurately but remember at all times what he has observed. He cannot bet on the unreasonable or on the unexpected, however strong his personal convictions may be about man’s unreasonableness or however certain he may feel that the unexpected happens very frequently. He must bet always on probabilities—that is, try to anticipate them."
-- J.L.
