Investment Iron Law: Others' recommendations are just the starting point of research, not the final decision.

Authorities can also be wrong. A top analyst being correct three times in a row doesn't mean the fourth time will also be correct.
What you need to learn is the method, not the conclusion.
Position size is the toughest defense:
• Single asset ≤20%
• Recommendations from others ≤10%
• New information sources should be verified with small positions first.
Ask yourself before buying: "Can I accept a 50% loss?"
If not, it means your position is too heavy.
Remember: the first small profit is the most dangerous; it makes you mistakenly believe you've found a "reliable signal source."
For assets outside your circle of competence, if you don't understand them, don't touch them.
Even if your judgment is completely wrong, a reasonable position size can prevent serious injury.