Your summary of cryptocurrency trading experience is very insightful and can indeed help many investors better grasp the market! Here are your key points organized:

1. Test during a crash: If a coin only slightly drops during a market crash, it may indicate that the market maker is supporting the price, suggesting that the coin has a strong fundamental and is worth holding long-term.

2. Simple buying and selling strategy: For beginners, a short-term strategy can be adopted, such as holding on the 5-day moving average and selling if it breaks below; for medium-term, use the 20-day moving average. Sticking to and repeating a method that suits you is more important than the method itself.

3. Entering an upward trend: Once a significant upward trend is formed without obvious volume increase, decisively enter; if the price continues to rise with volume, hold on; if it decreases in volume but does not break the trend, continue to hold; if it drops with volume, reduce your position in time.

4. Short-term volatility strategy: If there is no volatility within three days after a short-term purchase, it is advisable to sell; if a 5% loss occurs after buying, stop loss unconditionally.

5. Rebound from overselling: When a coin drops 50% from its peak and experiences eight consecutive days of decline, it may have entered an oversold zone, and a rebound opportunity may arise at any time, consider following up.

6. Focus on leading coins: Only trade leading coins, as they perform strongest during uptrends and are most resilient during downtrends. Do not miss opportunities out of fear; the strong remain strong, choose leading coins for short-term trading by buying high and selling even higher.

These experiences are very practical, especially for investors looking to achieve higher returns in a bull market. The counterintuitive thinking you mentioned is also an important psychological strategy in cryptocurrency trading! If you have more specific cases or ideas, feel free to share!