复盘“五大泡沫指标”，高盛认为“当下更像1997而非1999，AI牛市还有下半场”

Core Viewpoint - Goldman Sachs indicates that the current AI-driven stock market surge is not in a bubble phase comparable to the macro bubble of 1999-2000, suggesting that the market resembles the mid-bubble years of 1997 or 1998 instead [1][10]. Group 1: Current Market Analysis - Despite high valuations, the AI-driven bull market may still have room to grow, and exiting too early could result in missed gains [2][20]. - Current credit spreads and volatility remain low, providing a cost-effective opportunity for investors to manage risks using options [3][18]. - The macroeconomic indicators do not show signs of imbalance similar to those seen in the late 1990s, indicating a healthier financial environment [10][12]. Group 2: Historical Comparison - The report outlines five key indicators of macro bubbles from the late 1990s, including a massive investment boom, peak profitability, rising leverage, external crises driving capital inflows, and warning signals from credit and volatility markets [7][9]. - Current AI investment levels, while increasing, are still below the peak levels seen in the telecom investment boom of 2000, suggesting a more moderate investment climate [11]. - Corporate profitability remains stable, with no signs of deterioration, contrasting with the late 1990s scenario where profit margins peaked [11][12]. Group 3: Potential Signals and Risks - The report identifies potential "1998-style" turning points, such as accelerating investment plans from AI giants and private companies, which could indicate a shift in the market [14][15]. - There is a rising trend in debt financing for data center investments, which could signal increasing financial pressure on companies [16]. - External factors, including foreign government investment commitments, could play a role similar to the capital inflows seen in the late 1990s [16]. Group 4: Investment Strategies - Investors are advised to balance participation in the ongoing AI bull market with risk management strategies, as the current environment resembles 1997 rather than 1999 [17][20]. - Utilizing options for "offensive and defensive" strategies is recommended, as the low volatility environment allows for cost-effective risk management [18]. - Preparing for potential credit spread widening and long-term equity volatility increases is prudent, as historical trends suggest these could occur even in a bull market [19].