His list of ‘Essential Qualities of the Speculator’ and ‘Laws Absolute” show the timeless value of his insight:

1. Self-Reliance. A man must think for himself,must follow his own convictions. George MacDonald says: “A man cannot have another man’s ideas any more than he can another
man’s soul or another man’s body.” Self-trust is the foundation of successful effort.
 

2. Judgment. That equipoise, that nice adjustment of the faculties one to the other,which is called good judgment, is an essential to the speculator.
 
3. Courage. That is, confidence to act on the decisions of the mind. In speculation there is value in Mirabeau’s dictum: “Be bold, still be bold; always be bold.”
 
4. Prudence. The power of measuring the danger, together with a certain alertness and watchfulness, is very important. There should be a balance of these two, Prudence and Courage;Prudence in contemplation, Courage in execution.
Lord Bacon says: “In meditation all dangers should be seen; in execution one, unless very formidable.”
Connected with these qualities,properly an outgrowth of them, is a third, viz:promptness. The mind convinced, the act should follow. In the words of Macbeth; “Henceforth the
very firstlings of my heart shall be the firstlings of my hand.” Think, act, promptly.
 
5. Pliability. The ability to change an opinion,the power of revision. “He who observes,”says Emerson, “and observes again, is always formidable.”
The qualifications named are necessary to the makeup of a speculator, but they must be in well-balanced combination. A deficiency or an overplus of one quality will destroy the effectiveness of all. The possession of such faculties, in a proper adjustment is, of course, uncommon. In speculation, as in life, few succeed,many fail.

These are his ‘Laws Absolute’:

1. Never Overtrade. To take an interest larger than
the capital justifies is to invite disaster. With such an
interest a fluctuation in the market unnerves the
operator, and his judgment becomes worthless.

2. Never “Double Up”; that is, never completely and
at once reverse a position. Being “long,” for instance,
do not “sell out” and go as much “short.” This may
occasionally succeed, but is very hazardous, for should
the market begin again to advance, the mind reverts
to its original opinion and the speculator “covers up”
and “goes long” again. Should this last change be
wrong, complete demoralization ensues. The change
in the original position should have been made moderately,
cautiously, thus keeping the judgment clear
and preserving the balance of the mind.

3. “Run Quickly,” or not at all; that is to say, act
promptly at the first approach of danger, but failing
to do this until others see the danger, hold on or close
out part of the “interest.”

4. Another rule is, when doubtful, reduce the amount
of the interest; for either the mind is not satisfied with
the position taken, or the interest is too large for
safety. One man told another that he could not sleep
on account of his position in the market; his friend
judiciously and laconically replied: “Sell down to a
sleeping point.”