On Friday, June 12, SpaceX is set to make its public-market debut in what is expected to be the largest IPO in history. And it likely won't be the last blockbuster of 2026 — Anthropic, OpenAI, and Databricks are all reported to be preparing to follow suit.

With so much attention focused on these historic debuts, we took the opportunity to study how the biggest market debuts of the past actually performed. Click here to view what we found: Measuring Market Debuts. 

What the data shows

We compiled the 20 largest U.S. IPOs and direct listings by valuation at the offer and tracked total return at three key points: the first day of trading, one year later, and three years later.

The results are a useful reminder: a strong debut is no guarantee of a strong investment. For roughly half of these companies, an investor who bought in on IPO day had either broken even or lost money three years later.

Why this happens

We believe investor psychology explains much of this pattern. An IPO is, at its core, a fundraising event. Companies go on roadshows to court institutions and large investors, and that marketing — amplified by social-media buzz — tends to build excitement that drives a sharp jump on the first day of trading.

Over time, though, fundamentals reassert themselves. As the initial enthusiasm fades and early buyers take profits, prices often drift back toward what the business is actually worth.

Our take on the IPO wave ahead

The attached material lays out the full data behind this pattern. With several landmark debuts on the horizon, we believe it's a crucial moment to apply a disciplined, fundamentals-focused lens — not get swept up in the excitement of opening-day headlines.