In the face of heightened macroeconomic uncertainty and ongoing geopolitical tension, the stock market continues its march higher. The S&P 500 index (^GSPC +0.22%) has risen 10% in 2026 (as of May 27), keeping up the momentum from double-digit gains in the prior three years.

While this backdrop makes it easy for investors to relax, the smart ones are always thinking of ways to improve the chances of success. And now is a great time to do just that.

Here are three things long-term investors should do before June arrives.

Adjust to target balances

Every single investor is different. Based on their specific goals, they might have set certain rules that they choose to follow when it comes to portfolio management.

For example, investors might limit the percentage of a portfolio’s assets that can be in any individual stock. Or, there might be certain requirements for sector exposure. This requires a fresh look at your holdings, pushing you to sell positions and buy new ones.

As May comes to a close, it’s a good time to adjust your portfolio to ensure you’re staying within your target allocations.

Increase diversification

We all want to own the best stocks. However, it’s not a good idea to put all of your eggs in one basket. This introduces concentration risk, as the portfolio will start to depend heavily on a single position’s success, which isn’t guaranteed.

This is why it’s important to think about portfolio diversification. It’s smart to own businesses in different industries that serve different end customers.

Moreover, in June, investors might want to consider geographic diversification. If you only own an S&P 500 index fund, then there’s a big focus on the U.S. Gaining exposure to international equity markets might make sense, such as with the Vanguard Total International Stock ETF  (VXUS +0.08%).

S&P 500 Index

Today’s Change

(0.22%) $16.43

Current Price

$7580.06

Maintain a long-term mindset

Another thing investors can do before June arrives is adopt the right mentality. It’s easy to get caught up in which stocks to own, but investors might neglect their temperament, which is critical to success.

These days, investors are bombarded with so much information. It’s difficult to separate the signal from the noise. And this can force you to start thinking more about the short term, leading to harmful portfolio decisions.

This is a huge mistake. Time in the market matters much more than timing the market. Investors must always remember this. It’s never a bad idea to refresh your perspective.