[CITIC Construction Investment: The AI ​​industry chain is still the main line in the medium term] On September 28, CITIC Securities Research Report believed that the main reason for the shrinkage of A shares last week was trading and seasonal factors, and a restorative rebound is expected after the holiday. The overseas main line has shifted to "reacceleration + reflation + interest rate increase". The U.S. economy has moved from a K-shaped differentiation to a comprehensive recovery, but cost pressures remain. Long-term interest rates have soared, real interest rates have risen, Europe and Japan have followed up with interest rate hikes, and global financial conditions have tightened. The stronger RMB exchange rate provides a certain buffer, but the constraints of tightening external liquidity are difficult to completely lift in the short term. Under the combination of external interest rate disturbances that have not subsided and internal pre-holiday shrinkage that needs to be repaired, it is recommended to maintain a balanced and flexible offensive and defensive configuration. Offensive end: The AI ​​industry chain is still the main line in the mid-term. Once market enthusiasm recovers, the technology sector will often see the most obvious compensatory gains; industrial metals may be suppressed by the interest rate hike cycle, but fundamentals are still supportive, so focus on callback allocation opportunities. Defensive end: It is recommended to use low valuation, high dividends and cash flow certainty as the bottom position. Non-banks have both valuation and performance resilience, and the bank dividend bottom position is still there. In addition, the main line of resource products with hard supply constraints and rising prices is allocated as a hedge against the environment of rising external inflation rates and high valuations that put pressure on growth.