Most investors, including everyone here at the Motley Fool, would advise a beginner investor to build out a diversified portfolio of ASX shares as quickly as possible. Investing in the shares of any single company carries risk, but by spreading your money out between different companies that operate in different corners of the economy, you can mitigate a lot of that risk.
For example, a crisis in the banking sector will devastate an investor who only owns bank shares far more than one who owns one or two banks as part of a more widely diversified portfolio.
Saying that, most investors who do own a diversified portfolio would still have one or two stocks that they favour above the rest.
In my personal case, I have a clear favourite. In fact, it would be the ASX share I would put all of my life savings in if I had to choose just one stock to own for the rest of my life.
It's none other than Washington H. Soul Pattinson and Co Ltd (ASX: SOL).
Image source: Getty Images
Why Soul Patts would be my first choice as a forever ASX share
Washington H. Soul Pattinson, or Soul Patts for short, is an investing house. Instead of owning a chain of stores or selling a good or service, Soul Patts functions as an investing company, owning a vast portfolio of underlying assets on behalf of its shareholders. These assets include a massive portfolio of other blue chip ASX shares, private equity and venture capital investments. It will also include significant property assets if Soul Patts' proposed merger with Brickworks Ltd (ASX: BKW) goes ahead as planned.
We can already see a key advantage of picking Soul Patts as a single forever investment – inbuilt diversification.
But there's another reason why Soul Patts is one of my favourite ASX shares – its performance track record. Put simply, Soul Patts is one of the best long-term growers on the ASX. The company recently confirmed that its shareholders have enjoyed an average annual return of 11.2% per annum over the 25 years to 31 January 2025. That includes share price growth and dividends.
Speaking of dividends, Soul Patts also boasts one of the ASX's best dividend track records. It is the only ASX share that has increased its annual dividend every single year since 2000.
All of these factors, in my view at least, indicate an investment of the highest calibre. Given Soul Patts' inbuilt diversification as well, I would have no hesitation in choosing this company as my only investment if I had that proverbial gun to my head.
