Here is Trung Nguyen @SWI sharing is experience concerning the year 2025 about building his portfolio. He is talking in his newsletter « Sleeps well portfolio review »

I Am honored to be building a Sleep Well Portfolio with all of you. Sharing every ownership decision, along with my thoughts and the lessons behind them, has been very humbling. 2023 and 2024 were near-perfect, and in 2025, we hit a minor roadblock, but I am certain we are on the right path – owning irreplaceable monopolies and focusing on the right aspects – enduring growth.

A striking and recurring theme I experienced this year was that investors tend to overreact to short-term stock movements and underestimate the long-term drivers of the underlying businesses. Simply put, an investor’s average holding period is 6 months (and shortens each year), while mine is at least until 2037, when my daughters will take control of this portfolio. I am not under stress about this year’s underperformance. My patience and my focus on the long-term drivers of value are my edge and the reason why I sleep well. Any mistakes I make this year or next will be crucial to the performance of the next 10-20 years.

With a focus on deep fundamental research and long-term ownership, I am reasonably comfortable with the advice : ‘bet big when the odds are in your favour’. However, selling and cutting winners remains my weakness.

Last year, I learned that when selling, I should ‘sell my least loved business’. This year, I realized that no matter how good the business is, I need to be more ‘critical of my most loved stocks’, dissect them, and be ready to part ways (not clinging to stocks that I have spent considerable time on) for better opportunities. It’s a balancing act, given I don’t want to mistakenly ‘cut my flowers’.

During the year, I started the Best Buys series to force me to consider every position in the portfolio as if I were starting from scratch each month. As a result, I was able to trim CrowdStrike by half, a position I have held for over 5 years, from <$90/share (vs $525/share – sell alert).

Key lessons of 2025 :

1) So, no stock is ‘not for sale

Together with CrowdStrike, Sea Limited, Mercado Libre, and Veeva were held for over 5 years. All have suffered 30% drops multiple times, 50% once, and 80%+ once (Sea).

I am glad I didn’t sell then, but this year CrowdStrike’s stock has ventured into unimaginable valuations. The sale also pushed me into uncharted territory and set a precedent for all my future sales decisions.

From now on, all stocks are candidates for trimming ; to capture better opportunities or for cash until valuations come down to warrant further additions. Even Warren Buffett is sitting on nearly $360B cash (36% of the $1T market cap).

During the year, Wisetech also traded at close to 100x FCF (Q1 2025). CrowdStrike traded at 120x recently. In hindsight, Sea Limited trading over 30x FCF would have warranted a slight trim or a discussion of selling, given the 20% holding.

2) Avoid highly debated stocks – Intellego.

My next lesson is about my mistakes with Intellego. I have already written multiple articles on this (mistake ; cautioned others about the risk), but I add here that greater attention should be paid to working capital management. Quality of the revenue isn’t just about recurring revenue (89% of sales are from existing customers for Intellego), but I should also demand stable inventory days and receivable days. In other words, I demand that my business has inventory that sells and customers that pay. I relaxed these parameters for Intellego, given its early stage in the business/technology, where it needed to offer incentives (extended payment terms) to attract early, large international customers. Additionally, investing in smaller-cap companies will require more stringent parameters, as outlined in this article.

Now, my Intellego’s shares are treated as if I own a private unlisted business. Regardless of whether it is relisted on the Nordic Nasdaq, I hope that only a few actors are bad apples and that the company can continue to serve real hospitals and save lives. Even if all else fails, Intellego’s 10.5% ownership stake in one of its partners, HAI Solutions, may be worth something. HAI Solutions has the first and only FDA-approved UVC Technology for Microbial Reduction on Needleless IV Connectors, a $1.5B global market, and has the exclusive right to distribute the product in China and to receive royalties on global sales. This thriller continues….but will be the last I watch before bed.