Why does an explanation make a loss easier to hold?

Why this matters. The comfort an explanation gives is real, and it is unrelated to whether the explanation is true or whether holding is right.

A position is down and you do not know why. Then a plausible reason appears — sector rotation, a macro print, a broad move — and the position becomes easier to keep. Nothing about the price changed.

What the explanation actually did

It converted the situation from unknown to known-and-bad, and those are different discomforts. Replicated: ambiguity is avoided at a cost — Ellsberg (1961), which this course met in Why is a stated 40% chance easier to sit with?. A reason relieves ambiguity whether or not it relieves the problem.

So the relief is genuine and it is evidence about your state, not about the position.

The trap that follows

The relief attaches to the wrong thing. Because the explanation feels like progress, it substitutes for the decision: now I understand it stands in for therefore I should hold it. The second does not follow from the first.

Course 2 covers what this looks like while it is happening, in Why do new reasons to hold appear only after the price falls?. Here the point is the mechanism: an explanation is a comfort with a decision smuggled inside it.

A test the explanation has to pass

Ask whether the same reason would have been offered had the position been up. If the macro print explains a fall and would equally have explained a rise, it explains neither; it is a caption. An explanation that carries information about the position names something that would have gone differently — and that something is usually already in your changed-mind line, or should have been.

The artefact

Two separate lines, and the separation is the whole technique: what I now believe is happening, and what I am therefore doing, and why that follows.

Written apart, the second line often turns out not to follow at all. Written together, it never gets tested.

Try it now

Take any explanation you accepted this week for a market move. Write the two lines separately. Check whether the second survives the split.