Regarding the pinning incident at the exchange in the past two days, the following experiences and lessons can be summarized:

1. **Avoid large positions in small cryptocurrencies**: Small cryptocurrencies tend to have poor liquidity and insufficient market depth, making them prone to severe price fluctuations (pinning) due to large orders. Therefore, one should avoid opening large positions in small cryptocurrencies.

2. **Open and close positions in batches**: If it is necessary to operate with a large position, it is recommended to adopt a strategy of opening and closing positions in batches to reduce market impact and risk.

3. **Limit order closing is better than take profit and stop loss**: When closing a large position, it is preferable to use a limit order closing mode rather than the take profit function in stop loss and take profit. Limit order closing can better control the transaction price and avoid unnecessary losses due to market fluctuations.

4. **Be cautious when participating in small cryptocurrencies**: Try to minimize participation in trades involving small cryptocurrencies due to their high risk, insufficient liquidity, and vulnerability to market manipulation or extreme market conditions.

In summary, trading in small cryptocurrencies carries significant risks, and one should strictly control positions, adopt a batch operation strategy, and prioritize using limit order closing. For ordinary investors, it is advisable to avoid participating in small cryptocurrency trading to reduce risk.