Jim Cramer warns that a hoped-for $4 trillion SpaceX could spark a “rotation” out of mega-cap tech

CNBC’s Jim Cramer said investor enthusiasm around SpaceX, including talk that the company could eventually become enormous, risks triggering a self-inflicted market “bearish problem.” In a post on X reported by Benzinga, Cramer warned that investors may be “floating” the idea of S&P 500 inclusion on top of what he described as his biggest fear: a $4 trillion valuation for SpaceX. He linked that scenario to potential selling pressure on major technology winners.

Cramer’s core claim was less about SpaceX’s prospects and more about how investors might reposition their portfolios. He argued that investors could be overreacting to expectations around SpaceX’s public debut and to speculation that it could later become a large index constituent, creating enough momentum for some holders to trim names that already ran.

In that same X post, Cramer suggested investors, in his words, may decide to sell “Nvidia, Apple, Amazon, Microsoft” to make room for the SpaceX story. The point, as presented in the report, was that investors often fund the next excitement by reducing exposure to companies that have already benefited from prior trends, even when those trimmed positions remain strong businesses.

The S&P 500 angle matters because index-linked products can amplify trading around inclusion decisions. On June 4, S&P Dow Jones Indices said it would not change eligibility criteria for adding mega-cap companies to the S&P 500, S&P MidCap 400 and S&P SmallCap 600 as a result of a consultation. In particular, it said there would be no changes to financial viability screens, the seasoning period, or the minimum investable weight factor (IWF).

Even without immediate eligibility changes, the “what if” remains relevant for large-cap tech. Microsoft, for example, is deeply tied to the AI infrastructure cycle through Azure and related platforms. In its FY2025 Q4 earnings materials, Microsoft described Azure’s role in AI workloads, including databases and services that support ChatGPT interactions, and it highlighted Azure’s expansion of AI infrastructure and datacenter buildouts.

Cramer’s warning, interpreted in market terms, is that investors trying to gain exposure to SpaceX in the near term may create an “opportunity cost” effect for today’s mega-cap technology leaders. If large investors raise cash by trimming widely held index names like Microsoft, Nvidia and Apple, those stocks can see relative pressure even if they are fundamentally unaffected. Any later index inclusion could also create mechanical buying when conditions are met, potentially shifting attention away from current index constituents.

There are several gaps in what the comments alone can support. Cramer cited a $4 trillion valuation, but that figure is presented as a fear scenario, not a disclosed target tied to official filings or pricing terms. The report also does not provide detailed evidence of expected fund flows out of specific tickers, and it does not show Microsoft responding to the claim. In that sense, investors are being asked to weigh market psychology and portfolio behavior more than concrete, company-specific disclosures.