Below is a concise interpretation of 20 trading concepts to help you quickly understand investment logic:

1. Market Rules and the Nature of Games

1. Bull and Bear Positioning Strategy

- Institutional investors accumulate slowly in bear markets, retail investors follow the crowd at high prices in bull markets (reverse operational thinking).

2. Differences in Risk Tolerance

- Retail investors cannot afford losses (emotional), institutional investors understand risk control (discipline).

3. Characteristics of Retail Investor Mentality

- Taking small losses without changing nature, not respecting market rules, blind trading.

2. Operational Logic and Risk Warnings

1. Contrarian Thinking on News

- Don't chase up on good news (beware of selling), don't panic on bad news (look for oversold opportunities).

2. Duration of Bull and Bear Cycles

- Bull markets usually last shorter than bear markets (bear markets take longer to bottom out).

3. Profit and Loss Psychological Paradox

- Be conservative when profitable, aggressive when losing (need to counteract human nature).

3. Trading Strategies and Discipline

1. Balance of Belief and Realization

- Investment must be secured with profits, empty talk of 'belief' is meaningless (beware of dogmatism).

2. Core of Trend Trading

- Give up on small fluctuations, focus on main upward/downward trends (avoid frequent stop-losses).

3. Contrarian Sentiment Indicators

- Be cautious during market euphoria (risk accumulation), lay out during quiet times (opportunities sprout).

4. Risk Control and Awareness

1. Dangers of Emotional Trading

- A single mistake can affect mindset, and one can also short in a bull market (need stop-loss discipline).

2. Pragmatic Stock Selection Principles

- Dark horses are to be encountered but not sought after, focus on targets with strong certainty (avoid gambling nature).

3. Group Effect Trap

- Beware of the collapse of 'consistency expectations' in popular cryptocurrencies (reverse thinking).

5. Use of Cycles and Trends

1. Multi-Cycle Analysis Framework

- Large cycles determine direction (like weekly charts), small cycles (like hourly charts) find entry points.

2. The Essence of Good and Bad News

- Washouts are often accumulation opportunities, chasing up often encounters bubble bursts (counterintuitive operations).

3. Trend Following Principles

- In a bullish trend, only go long, in a bearish trend, only go short (prohibit counter-trend holding positions).

6. Fatal Mistakes and Their Roots

1. Risk of Lucky Psychology

- Ignoring probabilities, a single stroke of luck can lead to catastrophic losses.

2. Volume-Price Relationship Signals

- Volatility without volume is prone to extremes (need to beware of trend changes), pay attention to volume to validate trends.

3. Warning of Excessive Profit Traps

- Mindless operations in extreme markets are unsustainable (beware of survivor bias).

4. Core Investment Contradictions

- Lack of understanding is the biggest risk, continuous learning is required to enhance trading skills.

Summary: These concepts revolve around 'counter-human nature, emphasize discipline, and focus on logic', the core is to overcome greed and fear, establish systematic trading strategies, and avoid becoming a 'retail investor'. In actual operations, it is necessary to flexibly apply in conjunction with specific market environments.