Have you ever lost a lot of money by stubbornly holding on?

The truth is right here in this chart!
The most dangerous reference point in investing is not the market price,
but the position in your mind of "not willing to admit you've already lost."
This is a bit counterintuitive:
Prospect Theory rewrites "people are creatures seeking gains" into "people are creatures guarding reference points," and often we think we're pursuing gains, but actually we're maintaining our self-narrative.
Small profits are taken quickly, big losses are stubbornly held onto, risk aversion when profitable, risk seeking when losing.
Have you ever thought about why this happens?
So, the most dangerous reference point in investing is not the market price,
but the position in your mind of "not willing to admit you've already lost."
For example, we often add to positions to recover costs, treating the historical high as the money we should have had.
Sunk costs should not influence major decisions; if we set aside the narrative, it should be: not holding onto costs, but maintaining the system.
Don't seek to break even, seek compound interest.
Don't prove yourself, preserve your chance to bet again.