Castlebay Monthly: December 2025

Callum Dunbar
Dec 9, 2025
5 min read

Welcome to the final newsletter of the year.

It has been another rollercoaster of a year in markets and in life and our main article this month digs into the biggest lessons we can take from it. There is always something new to learn, even for those of us who have been doing this for decades.

The festive season is now in full swing. You may have been lucky enough to secure the M&S Tom Kerridge Beef Wellington for a mere £195. If not, I am certain the usual mountain of festive food will do the trick and add a couple of pounds all the same. A small seasonal tip: avoid the gym in early January, as it is full of people trying to undo December in a single week. With that said, you may spot a few of us there attempting to do just that.

Enjoy this month's instalment of our newsletter. It is packed with ideas and links that you may find interesting. As always, we’re here if you'd like to discuss how any of these ideas might apply to your unique situation. Also, if you would like to add your children, other family members or even friends to this email distribution list, please drop us a line.

Enjoy this month's instalment of our newsletter. As always, it is packed with links that you may find interesting.

The Stock Markets

2025 In Review

As we enter December, with one month still to go in 2025, there is already much for investors to reflect on.

The year began with the inauguration of President Trump, capping a year of elections that saw significant political change across the globe. What followed was a period of uncertainty and theatre around US tariffs that sent markets into a month of turbulence. Elsewhere, peace deals have begun to de-escalate conflicts that dominated headlines for years, while the AI revolution has continued to reshape industries and capture imaginations.

Despite periods of genuine chaos (including a sharp market decline that saw global equities fall by around -19%), it looks likely that 2025 will deliver another year of positive returns for equity investors.

We know from our conversations with clients that the period from March to April was an uncomfortable period for many. While these periods of decline and uncertainty are always unpleasant at the time, they remind us of the patience and discipline required to become successful long-term investors. The anxiety of early April has been rewarding for those who stayed invested.

While markets are forward-looking and already concerned about what 2026 could bring, there is value in pausing to look back. The events of the past year offer lessons that can serve us well in the years ahead.

Knowing What Will Happen Doesn't Tell You How Markets Will React

The tariff announcements in early April provided a striking lesson in the limits of information.

On 2 April, the Liberation Day tariffs announcement confirmed what many had expected: sweeping tariffs were on the way. Markets, which had been declining in March, fell sharply as uncertainty took hold. Yet just a few days later, on 8 April, with uncertainty arguably at its peak and no clear resolution in sight, the market quietly found its bottom and began to recover.

Those who knew tariffs were coming had no advantage. The information was widely available. What nobody could know was how and when the market would respond. This is why we focus on planning rather than predicting.

Long-Term Planning Beats Short-Term Prediction

It is rare for the world to undergo a shift as significant as the one we are living through with artificial intelligence. It is genuinely difficult to imagine what daily life will look like in five years, let alone how businesses, industries, and economies will adapt. However, we're confident that the human ingenuity that has seen us adapt and prosper through previous technological revolutions will do so again.

The knock-on effects for financial markets are equally unknowable. And yet, this uncertainty is not new; it is the permanent condition of investing.

Fortunately, the long-term game we are playing is not the short-term game being reported on by financial media. A solid financial plan (an appropriate asset allocation, a margin of safety, and the discipline to stay invested through volatility) remains the foundation for long-term success. Let us resolve to hold onto this truth, especially when the future feels more uncertain than usual.

Thank You

In summary, 2025 has reinforced a timeless principle: we cannot predict but we can prepare. These lessons, earned through a year of turbulence, will steady you when markets next test your resolve.

As we approach the end of another year, let us continue to focus on what we can control: maintaining robust financial plans and practising patient, disciplined investing.

Life is for Living

While we always encourage smart saving and financial prudence, enjoying the life you're working hard to build is just as important. That means making space for experiences, community and a little fun now and then!

Here’s a roundup of upcoming events and dates for the diary that might pique your interest. Treat yourself because balance is key; life is meant to be lived.

Feeling festive: RSNO 'The Snowman' Live [Scottish venues, 17th - 20th December]

Something for the weekend: Edinburgh Christmas Markets [Princes Street Gardens, until 4th January]

Inspiration for Christmas Dinner: 'A Mary Berry Christmas' [BBC One, Wednesday 17th December at 21:00]

Read

9 Questions to Help Understand Life’s Greatest Mystery — You [8 minutes]. Nine thought-provoking questions.

How To Have A Happy Retirement: 4 Secrets From Research [8 minutes]. Avoid the common pitfalls and embrace this new chapter with joy and purpose.

The Gifts We Give Our Kids [7 minutes]. Are you ready to give your kids the most valuable gifts that money can’t buy?

A Picture is Worth a Thousand Words

The Castlebay Corner

The Festive Period is upon us As the year winds down and the festive lights go up, we just want to take a moment to say a heartfelt thank you.

To our clients, colleagues and friends, you’ve been at the heart of everything we’ve done this year. Your trust and support means so much to us and we’re incredibly grateful to help those of you on your financial journey.

From all of us at Castlebay, we wish you a joyful Christmas filled with good company, great food, and a well-earned pause. Here’s to a peaceful holiday season and a fresh new year full of promise.