AI总结
核心结论 (Core Conclusion)
- 中文：投资者无需纠结指数基金是否包含SpaceX等新上市热门股，这种针对IPO的择时选基行为对长期投资回报影响微乎其微。
- English：Investors should not stress over whether their index funds include newly listed high-profile stocks like SpaceX; choosing an index based on such criteria is unlikely to boost long-term investment returns.
结构逻辑 (Structure & Logic)
- 现象引出：SpaceX上市后，被纳入部分指数，导致投资者在不同指数基金（涵盖与不涵盖）之间面临选择焦虑。
- 核心论点：对比广泛市场指数（如Vanguard Total Stock Market）与精选指数（如S&P 500），证明两者的长期收益差异并不显著。
- 风险分析：指出新股上市初期通常波动剧烈，且往往存在市场调整后的表现不佳风险，指数纳入规则（如盈利门槛、上市后时限）起到了筛选缓冲作用。
- 投资建议：回归被动投资本质，强调资产配置和成本控制远比纠结个股构成更重要。
关键信息 (Key Information)
- 公司/股票：SpaceX (SPCX)、Meta (Facebook)、OpenAI、Anthropic。
- 基准指数：S&P 500, Vanguard Total Stock Market ETF (VTI)。
- 核心概念：IPO波动率、指数覆盖范围、浮动份额(Float)、被动投资逻辑。
问题与回答 (Questions & Answers)
- 问题：被动投资者应如何看待指数基金对SpaceX等巨额IPO的纳入差异？
- 回答：不必纠结。数据表明，涵盖广泛IPO的指数与严格筛选的指数在长期回报上差异很小，且指数本身具备的流动性调整机制已能有效管理风险。
正文
People gather in Times Square where electronic billboards display SpaceX branding during the company’s initial public offering.
SpaceX branding in New York’s Times Square during the company’s initial public offering. Shuran Huang for WSJ
Being a passive investor means you don’t pick stocks. But you still have to pick an index. And different indexes have different approaches to huge new listings.
Following the addition of SpaceX SPCX 2.06%increase; green up pointing triangle after its initial public offering to many stock indexes last week, passive investors are suddenly faced with a stark choice in benchmarks. Do they want one that now includes Elon Musk’s newly listed company with a rocketing valuation, or one that doesn’t.
Surprisingly, the diverging approaches might not make a huge difference for investors who focus on broad-based investment vehicles that keep costs low.
Among some of the largest exchange-traded funds, the Vanguard Total Stock Market ETF tracks an index that will now include SpaceX. But the giant ETFs tracking the S&P 500 index won’t have it.
Investors could be on either side of this. Maybe they feel that they are missing out on great companies like SpaceX if their index doesn’t have them. Or they might want to avoid overhyped debutantes until the dust settles on the latest IPO boom.
This is a variation on a basic question passive investors face. Should they aim to replicate the whole market, or just the bulk of it? Vanguard’s total-market ETF tracks an index with almost 3,500 companies, and which can add IPOs after just a few days of trading. The S&P 500 tracks not only larger companies, but waits much longer after an IPO and has profitability criteria for inclusion.
The reassuring news for passive investors is that, in recent years, it hasn’t made a huge difference in returns. For comparison’s sake, consider Vanguard’s total-market index ETF versus its S&P 500-tracking ETF. Over the past decade through Thursday, the S&P 500 ETF has returned an annualized 15.6%, according to FactSet data. The total-market index ETF has returned 15.1%.
That isn’t a huge gap. And it is just one precise interval. Any variation within that span, or depending on when you entered and exited, could easily have generated a different outcome. Over the last two years, for example, the total market ETF has returned an annualized 18.9% versus about 18.5% for the S&P 500 ETF.
Investors who are skeptical of IPO hype aren’t crazy. Newly listed companies in the U.S. historically have, on average, a poor market-adjusted track record in their first couple of years from where they end trading in their first session.
Looking at the most recent IPO boom year, back in 2021, the S&P 500 index outperformed several major total-market indexes, according to FactSet data.
Case closed then? Not quite. IPO vintages vary just like anything else.
In 2012, when Meta Platforms, then Facebook, went public, that year’s IPOs from their first-day closing price on average outperformed the broader market over the next three years, according to data compiled by University of Florida finance professor Jay Ritter. In 2012 and 2013, the S&P 500 index’s annual returns trailed several total-market benchmarkets, according to FactSet data.
The types of companies going public matters, too. IPOs of very large companies, with $1 billion or more in inflation-adjusted, past-year sales pre-IPO, on average historically from 1980 to 2024 just about matched the market’s performance over three years from their first-day closing price, according to Ritter’s data. And IPOs of unprofitable tech companies with $100 million or more in inflation-adjusted past-year sales? Those actually beat the market by more than 11% over three years, on average.
WSJ’s Asa Fitch breaks down what investors can expect from the other big IPOs of 2026 — OpenAI and Anthropic — as SpaceX makes its public debut. Photo Illustration: Rachel Rogers
Of course, in any given year, across a vast market, with IPOs usually representing just a sliver of companies, it is quite difficult to attribute any broad index’s performance to having or not having new listings. The point is just that it is difficult to predict any of these outcomes, especially over the shorter term.
Could SpaceX’s sheer size and magnitude change the calculus? It has already traded at prices that make it one of the U.S. market’s largest stocks.
However, SpaceX’s limited float will curtail its index impact. Most indexes adjust a company’s market value by how much of it is freely available to trade. SpaceX initially sold less than 5% of its stock in its offering.
That will rise as more shares are freed up for sale. But according to estimates by Morningstar analyst Zachary Evens, SpaceX’s float is unlikely to exceed 50% after a year. The percentage that is floating can also depend on the degree of insider selling, as well as new stock issuance by the company.
The bottom line for a self-styled, passive investor who actively moves in and out of different indexes for near-term performance reasons, or to avoid (or include) a certain stock? They will find themselves in the same stock-picking and market-timing quandaries they had initially set out to avoid—with potentially little ultimate benefit.
How much you should invest, how you should spread funds across asset classes and how much you should pay managers, are far more consequential decisions.
Appeared in the June 23, 2026, print edition as ‘Does Your Index Fund Have SpaceX?’.