MTTM Podcast Episode 531 – Surviving an AI stock bubble & the best time to invest

2 min Read Published: 21 Dec 2025

Listen to Episode 531

This week, we discuss research into the best investment strategy to navigate a potential AI stock market bubble. We also explore the 'calendar effect' to find out when is the most profitable time of year to start investing your money.

Support the podcast

Remember to like, subscribe and follow us on all our socials. You can also support the Money to the Masses podcast by visiting our dedicated podcast page.

Every time you use a link on the page we may earn a small amount of money for our podcast. We only use affiliate links that give you an identical (or better) deal than going direct. Thank you for being an incredible part of our community. Your support means the world to us.

Watch the video version of the podcast below:

Listen to other episodes and follow the show by searching 'Money to the Masses' on Spotify or by using the following links:

Listen on iTunes    Listen on Spotify     via RSS

Free Pension Review

Book a free pension review

Our partner Unbiased will arrange for a qualified, FCA-regulated adviser to contact you.

  • Look at your total retirement picture
  • Get an unbiased review of your options and goals
  • Free and without obligation

Provided by our partner
Book a free review*

Episode 531 Podcast Summary

Navigating a potential AI bubble

Summary

Using research from Fidelity that analysed the dot-com bubble (1998–2001), we examine how different investment strategies performed during a tech-driven market surge. We discuss why a balanced "realist" approach often outperforms attempts to time the peak of a bubble.

Key insights

  • The "Realist" strategy: In the dot-com study, a balanced portfolio of tech and defensive stocks returned 77% over four years, outperforming many complex strategies that tried to time the market.
  • The Risk of FOMO: The "disaster switch" - moving entirely into tech at the height of the bubble due to fear of missing out - resulted in the lowest returns (20%).
  • Market concentration: Currently, six stocks represent roughly 30% of the S&P 500, highlighting the importance of diversification outside of tech that is heavily AI-focused.
  • The long view: Investing is like walking a mountain range; you must be prepared to go through "valleys" (market dips) to reach the next, potentially higher peak

Pension Credit: Unclaimed benefit worth £4,300 per year on average

Summary

We share research into the FTSE 100's performance since 1984, looking at every 5-year investment window. The data reveals a significant "seasonality" or calendar effect that points to certain weeks being statistically more favorable for starting an investment.

Key insights

  • Seasonality: Five of the top 10 best days to start a 5-year investment in the FTSE 100 occur between Christmas and the 10th of January.
  • The January effect: This positive trend extends through the first month of the year, with eight of the top 10 best days occurring before the end of January.
  • September slump: Conversely, five of the top 10 worst days of the year to invest historically fall in September.
  • Time in the market: While averages show seasonal trends, the most important factor is your total investment timeframe, as compounding matters more than "cherry-picking" a single day.

Resources

Links referred to in the podcast:

 

If a link has an * beside it this means that it is an affiliated link. If you go via the link, Money to the Masses may receive a small fee which helps keep Money to the Masses free to use.

MTTM AI (beta)
X
I’m MTTM AI (beta), powered by DaMoney. I can help with personal finance questions. I’m an AI tool, not a financial adviser. Answers are for information purposes only and do not constitute financial advice. Always verify responses with your own research and seek professional advice. By using this chat, you agree to our Terms of Use.
Go ahead, ask me a question