The S & P 500 broke past 5,000 for the first time ever this week, but investors will see if the momentum can stick in the week ahead with more inflation data and earnings results on deck. The 5,000 milestone does not represent technical resistance for the S & P 500, but a nice, round number has held psychological significance for investors in the past — and could represent a level at which stocks can further rally or consolidate from here. The broader index first crossed 4,000 in April 2021. The debate over whether stocks continue their record-breaking move or break down is a point of contention for investors. Some expect an expanding, albeit slowing, economy will continue to power earnings growth and drive stock prices higher. But others worry the milestone is a reason to be more cautious and advise traders to use the occasion to take some profits, especially in what appear to be richly valued mega-cap tech stocks. Worrying signals they cite include rising bond yields, with the 10-year Treasury yield ticking higher to 4.15% this week. Wharton Business School’s Jeremy Siegel told CNBC’s “Closing Bell” on Thursday: “Remember, when we think about 5,000, it wasn’t long ago when we had some very big names telling us the S & P was going down to 3,600,” “Stocks, for the long run, there’s going to be volatility. I don’t advise playing the game of being a short-run trader, I know a lot of people do,” Siegel continued. “But I don’t think right now the market is overvalued for a long-term investor by any means.” But Karim El Nokali, investment strategist at Schroders, said investors should proceed with caution: “Usually, when the market sees those big round numbers — sometimes the first time it encounters those numbers — you see a bit of a retracement.” On Friday, both the S & P 500 and the Nasdaq Composite were headed for their fifth straight week of gains, and their 14th winning week in 15. Better data supports the bull case The recent optimism in markets can be traced to a combination of better-than-expected earnings results, as well as signs of easing inflation, a stronger labor market and a more resilient economy — all of which are pointing to a more rosy outlook than many anticipated heading into 2024. Thus far, roughly two-thirds of S & P 500 companies have reported fourth-quarter earnings, and the results are showing signs of strength after a lackluster start to the season. FactSet data shows S & P 500 earnings are tracking to have risen 2.8% in the fourth quarter, which would be a second straight quarter of earnings growth, and some expect that positive momentum will remain intact in the weeks ahead. “What we’re seeing is companies have done a really great job preserving their profit margins. And we’ve actually seen even a little bit of an acceleration or re-acceleration again, in some of the profit margins and that’s been encouraging for us to see on the earnings front,” said Tony Welch, chief investment officer at SignatureFD. More big earnings results in the week ahead include Arista Networks, as well as Marriott International, Occidental Petroleum, Deere and Applied Materials. Wall Street gets more inflation data next week, and investors expect it will continue to confirm the recent downward trend. In fact, on Friday, stocks rose after December’s inflation reading was revised even lower than previously reported. January’s consumer price index is due out Tuesday, with prices anticipated to have risen 0.2% for the month, and increased 2.9% on a year-over-year basis, according to a Dow Jones consensus estimate. That would be about in line, or lower, from readings of 0.2% and 3.4% the prior month. A cooler-than-expected print has the potential to be greeted with enthusiasm, sending the S & P 500 even higher. However, a hotter print could throw cold water on the Wall Street rally by sending Treasury yields higher. But SignatureFD’s Welch expects the bull market will continue in 2024, and predicts any market weakness will be “benign.” He recommends traders add to small cap stocks, which he expects will outperform later in the year. “Our anticipation is that the bull will continue throughout the duration of 2024. Just like any year, there’s going to be volatility and corrections along the way, but those should, in our view, those should remain benign in 2024,” Welch said. “So if you do get any market weakness, that is an opportunity to add exposure if you haven’t already.” A ‘thin and thinning rally’ Others worry the divergence between mega-caps and the rest of the market is starting to look untenable, and points to a drawdown in the near term. The S & P 500 is up by 5% this year, with Nvidia higher by more than 40%. This week, semiconductor designer Arm Holdings surged 65% after reporting strong earnings and making a rosy profit forecast. On the other hand, the equal-weighted S & P 500, which gives the same value to each stock in the index regardless of their market capitalization, is higher by just 0.6% in 2024. And the small-cap Russell 2000 index of small cap stocks is lower by nearly 1% this year. “Small caps have given up all their outperformance for the fourth quarter, and we’re back to what we had for most of 2023, particularly in the summertime, which is a thin and thinning rally here as the S & P moves higher,” Jason Hunter, head of technical strategy at JPMorgan, told CNBC’s “Closing Bell” on Thursday. “So it’s something that’s been able to, as we just said in a note, defy gravity here, despite the lack of market breadth and the repeated attempts for it to try and roll over, but it certainly isn’t a broad breadth and broadening rally at this point,” he added. “In our view, it’s something that makes it look like the trend is getting long in the tooth and setting up at least for a near-term pullback.” That said, Hunter said the market trend remains toward the upside, so long as the S & P 500 does not break below support levels at 4,800. “Our view is that we don’t quite reach 5,100 and 5,200 area, that we are going we stall out below that,” Hunter said. Other concerns abound, including greater geopolitical risks, political tensions in a U.S. election year, as well as a flare-up in concern around regional banks . This month, New York Community Bancorp shares dropped more than 25% after the Long Island bank reported a surprising fourth-quarter loss, a large loan loss reserve and slashed its dividend. Many investors expect the concerns are largely contained to NYCB . However, with investors just a little more than one month into 2024, many investors are seeking more clarity to see how the economy and earnings hold up, and how the Federal Reserve will act, before making a call on how stocks continue to perform. “I don’t think we’re leaning too heavily in any direction right now,” said Matt Kishlansky, principal at GenTrust. “This seems like a very coiled moment in either direction.” Week ahead calendar All times ET. Monday Feb. 12, 2024 2 p.m. Treasury Budget (January) Earnings: Arista Networks , Waste Management Tuesday Feb. 13, 2024 6 a.m. NFIB Small Business Index (January) 8:30 a.m. CPI (January) Earnings: MGM Resorts International , Airbnb , Welltower , Akamai Technologies, Marriott International , Howmet Aerospace , Molson Coors Beverage , Coca-Cola Co., Hasbro , Ecolab , Biogen Wednesday Feb. 14, 2024 Earnings: Occidental Petroleum , Albemarle , Kraft Heinz , Generac Thursday Feb. 15, 2024 8:30 a.m. Continuing Jobless Claims (02/03) 8:30 a.m. Export Price Index (January) 8:30 a.m. Import Price Index (January) 8:30 a.m. Initial Claims (02/10) 8:30 a.m. Empire State Index (February) 8:30 a.m. Philadelphia Fed Index (February) 8:30 a.m. Retail Sales (January) 9:15 a.m. Capacity Utilization (January) 9:15 a.m. Industrial Production (January) 9:15 a.m. Manufacturing Production (January) 10 a.m. Business Inventories (December) 10 a.m. NAHB Housing Market Index (February) Earnings: Deere , Applied Materials Friday Feb. 16, 2024 8:30 a.m. Building Permits preliminary (January) 8:30 a.m. Housing Starts (January) 8:30 a.m. PPI (January) 10 a.m. Michigan Sentiment preliminary (February)