Analysis of Regular Investment Strategy Adjustments for the Nasdaq 100 Index Amid High Shiller P/E Ratios

This analysis is based on social media discussions and market data, focusing on the regular investment strategy for the Nasdaq 100 Index amid historically high Shiller P/E ratios. The current S&P 500 Shiller CAPE ratio is 39.8, the second highest in over 140 years, only exceeded during the dot-com bubble period [1][2], reflecting the overall high valuation of U.S. stocks. The Nasdaq 100 Index closed at 24,647.61 points on December 17, 2025, down 2.07% from the previous trading day, and oscillated around the 25,000-point level that month [0], with increased volatility.

Discussions highlight the strategy adjustments proposed by bloggers: liquidating the Invesco Great Wall Nasdaq Technology Index Fund (a QDII product that attracted $541 million in inflows in November 2025 and tracks the Nasdaq Technology Index [3]) after one year of regular investment, then restarting daily regular investments to lock in profits. This operation reflects investors’ conflicting mentality in a high-valuation environment—worried about being trapped if the valuation bubble bursts, yet afraid of missing long-term upside opportunities after fully liquidating positions.

1. Dialectical Relationship Between High Valuation and Regular Investment
   : Most experts suggest long-term regular investors continue regular investments to avoid market timing mistakes, but can appropriately adjust regular investment amounts or portfolio structures [0]. The Shiller P/E ratio mainly reflects the overall valuation of the S&P 500; its reference to the Nasdaq 100 needs to consider the profit growth prospects of its components (mostly tech growth stocks), and direct analogy has limitations.
2. Balanced Strategy of Flexible Adjustments
   : The blogger’s “liquidate to lock in profits + restart regular investment” operation does not completely negate regular investment; instead, it locks in gains through phased position reductions and then uses a more flexible regular investment rhythm to cope with high-volatility markets, providing a risk hedging idea for long-term regular investors.
3. Investor Sentiment and Strategy Differentiation
   : Discussions reflect cautious bullish sentiment towards high valuations; investors focus on both the risk of missing gains (missing long-term growth) and the risk of being trapped (valuation correction), so strategy selection needs to be adjusted based on individual risk tolerance and investment cycle.

1. Valuation Correction Risk
   : The current Shiller P/E ratio is at a historical high; if the market undergoes valuation regression, short-term net value decline risks may occur [1][2].
2. Strategy Execution Risk
   : When adjusting regular investment strategies, if investors misjudge the “better entry timing”, they may miss upward trends or fail to intervene timely after corrections, exacerbating the risks of missing gains or being trapped.
3. Index Difference Risk
   : Directly using the S&P 500’s Shiller P/E ratio to judge the Nasdaq 100’s valuation may lead to misjudgment due to differences in component structure.

1. Long-Term Growth Opportunities
   : Most components of the Nasdaq 100 Index are tech leaders with strong profit growth capabilities; long-term regular investments are still expected to benefit from the development of the tech industry [0].
2. Advantage of Regular Investment Discipline
   : Adhering to regular investments can reduce the impact of short-term volatility through cost averaging; especially new investors should not pause regular investments due to short-term high valuations [0].

• The current U.S. stock Shiller P/E ratio is at a historical high, and the Nasdaq 100 Index has increased short-term volatility [1][2][0].
• Long-term regular investors can appropriately adjust strategies (e.g., flexibly adjust regular investment amounts, phased position reductions to lock in gains), but should not completely stop regular investments or liquidate positions; they need to balance the risks of missing gains and being trapped.
• The Shiller P/E ratio has limitations as a valuation reference for the Nasdaq 100; comprehensive judgment needs to consider the profit growth prospects of its components.
• Investors should choose appropriate strategies based on their own risk tolerance and investment cycle, avoiding over-reliance on short-term valuation indicators for timing operations.