As 2024 Ends, the S&P 500 Is Poised to Do Something It Has Only Done 6 Times Before. Here's My Plan.

The S&P 500 (SNPINDEX: ^GSPC) has long been the benchmark of performance for many investors. Because it comprises the 500 largest stocks listed on the U.S. index, it tracks companies from multiple industries, giving investors a good feel for how the overall market is doing.

Although the index was created in 1957, it is possible to extend it back to 1927 using the index's entrance. By looking at these annual returns, you can discover some interesting trends, including the one that we're heading into. So, what do the historical numbers say the market will do in 2025?

The market reflects the dot-com boom of the late '90s

The market has been incredibly strong during the past two years, as it has returned more 20% (assuming the 2024 returns -- now about 27% -- hold up to finish the year). That doesn't happen all that often. In fact, it has only happened six times since 1927.

The market is heading into year three of that run. What happened the previous six times the market returned 20% or more for two years in a row? The answer: It's a mixed bag.

• 1929 return: -8.4%
• 1937 return: -39%
• 1956 return: 2.6%
• 1997 return: 31%
• 1998 return: 26.7%
• 1999 return: 19.5%

If it's another year like 1937, investors may be in for some pain. However, it could also be like the late '90s, when investors enjoyed nearly five straight years of 20% or more returns.

What happened in the late '90s? There was a tech boom associated with the internet. That ended extremely poorly a few years after the run, but there was significant investing success during the rally.

The internet turned out to be a huge technological success, even if many of the companies involved with it didn't give investors great returns over the long term (although during the rise, they gave investors huge gains).

That sounds incredibly similar what is happening today, as artificial intelligence (AI) stocks are all the investing rage. Many people are predicting that the current AI revolution will have much the same impact on work and society as the internet did, so it's quite fitting to predict that the market will act much as it did in the late '90s.

What am I doing in 2025?

As we head into 2025, I'm planning on being an opportunistic buyer. If I see a company I like trading at a reasonable price, I'll invest. Otherwise, I'm perfectly content with just investing in a broad market index, like the S&P 500.

That way, if AI stocks do go down, it won't be as painful as being 100% invested in the AI universe. Now, the S&P 500 is heavily weighted toward some of these AI companies because the S&P 500 is a market cap-weighted index, so it won't be in the clear if there there is a pullback. However, various healthcare, financial, and consumer goods companies will help prop it up.

On another note, there's nothing special about turning the calendar to 2025. Although it marks a new year, the market is a continuous entity, so the calendar flip from 2024 to 2025 isn't really a great milestone to judge it by because there can be specific events that happen in the middle of a year that would truly define a new stage in the market.

With that in mind, the S&P 500 is still a great place to put money in the market because it is a fairly well-balanced index. However, if you're looking for more upside, there are some specific companies within that index that look like fantastic buys now, and I'll be scooping them up in 2025 as well.