One of the simplest ways for investors to reduce risk and improve returns over the long term is to diversify not only across sectors but also across regions.
While the ASX has no shortage of high-quality shares, it represents only a fraction of the global market. By combining local opportunities with world-class international businesses, investors can build portfolios that are stronger and more resilient.
With that in mind, here are my top picks from the ASX 200 and the S&P 500 for the month of September.
CSL Ltd (ASX: CSL)
CSL is one of the ASX's most successful growth stories. Over the past century, it is has transformed from being wholly owned by the Australian federal government to a global biotechnology powerhouse with operations in more than 100 countries and 29,000 employees.
The company's therapies and vaccines enjoy high barriers to entry, which protect its market share and allow it to generate consistent earnings. While recent results and restructuring news have spooked the market, CSL still managed to post double-digit profit growth in FY 2025.
And with cost savings and a planned spin-off of its vaccines arm on the horizon, as well as robust demand for immunoglobulins, the long-term outlook remains very strong for this ASX 200 share.
So, with its shares trading close to a 52-week low, CSL looks like a quality compounder on sale. For investors with patience, this could be an excellent time to add it to a portfolio.
Visa Inc (NYSE: V)
Turning to the U.S., Visa is a true global leader in payments. The company processes trillions of dollars of transactions annually across its network, benefiting from powerful tailwinds as the world continues its shift from cash to digital payments.
Visa shares have climbed an impressive 25% over the past 12 months but have recently pulled back from their highs. For long-term investors, that weakness could be an opportunity.
With its unrivalled global scale, brand recognition, and consistent ability to generate free cash flow, Visa has all the hallmarks of a long-term compounder.
Foolish takeaway
CSL and Visa may come from different markets and industries, but they share the traits that make them attractive to buy-and-hold investors. They have sustainable competitive advantages, strong cash generation, and long runways for growth.
By blending a world-class ASX healthcare giant with a U.S. payments leader, investors can enjoy the benefits of both homegrown stability and international growth.
