The S&P 500 Index (SP: .INX) has had a stellar run over the past 12 months.

Since this time last year, the benchmark US index has soared 31.6%, closing down 0.1% on Friday at 5,234 points.

Spurred by strong earnings results amid a resilient US economy alongside investor exuberance over pending interest rate cuts from the US Federal Reserve as inflation comes off the boil, the S&P 500 has notched a series of new record highs this year.

It's a similar story with the tech-heavy Nasdaq Composite Index (NASDAQ: .IXIC). And, here in Australia, with the S&P/ASX 200 Index (ASX: XJO).

The ASX 200 is up 0.4% in afternoon trade today at 7,804.4 points. That puts the Aussie benchmark index within striking distance of surpassing the 8 March all-time closing high of 7,847.0 points.

Turning back to US markets, here's what Goldman Sachs says could send the S&P 500 soaring another 15% in 2024.

To be clear, Goldman Sachs' base case remains for the S&P 500 to close the calendar year right around current levels, at 5,200 points.

But Goldman's analysts also foresee the possibility that ongoing investor exuberance with artificial intelligence could see the big tech stocks propel the index to 6,000 points by the end of 2024.

Or 14.6% above current levels.

According to Goldman's analysts (quoted by Bloomberg), "Although AI optimism appears high, long-term growth expectations and valuations for the largest TMT [technology, media, and telecom] stocks are still far from 'bubble' territory."

The broker also noted that the resilient US economy and potential Fed rate cuts have already been fully priced into the markets.

In order for the US benchmark index to soar to 6,000 points by year end then, they said, "A shift in the interest rate outlook without a deterioration in the economy is necessary for the market rally to broaden."

ASX investors looking to track the performance of the S&P 500 without buying all those stocks may want to run their slide rule over the SPDR S&P 500 ETF Trust (ASX: SPY).

The ASX-listed exchange-traded fund (ETF) provides investors with exposure to 500 of the largest US-listed companies. SPY aims to track the performance returns of the benchmark. And it comes with low management costs of just under 0.10% per year.

Over the past 12 months, the ETF has gained 33.7%.

As always, before you invest a single dollar in SPY or any other ASX share, be sure to do your own thorough research.

If you're uncomfortable with that, or just don't have the time, reach out for some expert advice.