"A formula for success in life and finance: never hold an investment that you would not be willing to purchase afresh today."
Source: TraderFeed: What Trading Teaches Us About Life
For more on sunk cost bias and how it affects (and subverts) our investment decisions:
- Sunk Cost Trap Definition | Investopedia
- How the Sunk Cost Fallacy Makes You Act Stupid
- Sunk costs - Wikipedia
- Sunk Cost Bias: How It Hinders Your Life and 4 Ways to Overcome It
- Freakonomics » Meditating on Those Sunk Costs