Analysis of Potential S&P 500 Additions in December 5, 2025 Rebalancing

On December 1, 2025, a Reddit user [1] asked for insights on stocks likely to be included in the upcoming S&P 500 rebalancing announcement on December 5, listing MRVL, VRT, CRH, SNOW, ARES, LNG, FERG, SOFI, and RDDT as potential contenders. The post noted VRT has a “strong case” and that added stocks often see a ~10% price boost from announcement to inclusion.

To be eligible for the S&P 500, stocks must meet criteria [0]: US-domiciled, market cap ≥~$20.5B, public float ≥10%, and high liquidity. Evaluating the listed stocks:

• Eligible
  : MRVL ($78.55B market cap), VRT ($68.52B, ~98.1% public float), SNOW ($83.86B), ARES ($34.59B, ~95.6% public float), SOFI ($35.01B), RDDT ($42.33B, ~70.3% public float)
• Ineligible
  : CRH (Ireland-domiciled), FERG (UK-domiciled), LNG (already an S&P 500 component)

Historical market data [0] supports the ~10% boost claim: SanDisk jumped 9% in after-hours trading post-inclusion announcement, while Super Micro Computer gained 12.5% in after-hours trading—aligning with the mechanical demand from passive funds tracking the S&P 500.

The most likely candidates are VRT (strong community support in the Reddit post, high market cap and public float) and ARES (previously highlighted in analyst reports as a top candidate, meeting all eligibility criteria).

• Discretionary Committee Role
  : The S&P Dow Jones Indices committee has sole discretion in selections, considering factors like sector representation and market conditions beyond basic eligibility—meaning even strong candidates aren’t guaranteed inclusion.
• Passive Flow Impact
  : The ~10% price boost is driven by passive fund rebalancing, a short-term mechanical effect rather than fundamental valuation changes, though inclusion can improve long-term liquidity and institutional ownership.
• Eligibility vs. Likelihood
  : All eligible stocks meet the minimum criteria, but VRT and ARES stand out due to additional analyst/community support, distinguishing them from other candidates like SOFI (noted as “likely” but maybe not this Friday) and RDDT (a “hopeful candidate” without strong supporting data beyond the Reddit post).

• Risks
  :
  • Committee discretion means no guarantees of inclusion for any eligible stock.
  • Market conditions or unstated sector goals could prioritize other stocks not mentioned in the Reddit post.
  • Early price movements may already price in the ~10% boost, reducing post-announcement gains.
• Opportunities
  :
  • Short-term price gains for confirmed additions, driven by passive fund buying.
  • Long-term benefits like increased visibility and liquidity for included stocks, potentially attracting more institutional investment.

This analysis provides a structured evaluation of potential S&P 500 additions based on eligibility criteria, historical performance, and community/analyst insights. Eligible stocks include MRVL, VRT, SNOW, ARES, SOFI, and RDDT, with VRT and ARES as the most likely candidates for the December 5 rebalancing. Historical data indicates added stocks typically see ~10% price gains from announcement to inclusion, though this is not guaranteed due to the committee’s discretionary selection process and market dynamics. No prescriptive investment recommendations are made.