Capital Economics has sounded a cautionary note for investors, arguing that a flood of large initial public offerings and follow-on share sales could present a substantial test for equity markets. In a client note, Markets Economist Joe Maher highlighted that gross equity issuance historically accelerates during stock market booms and that recent activity resembles patterns observed near previous market peaks.
The research house pointed to fresh data showing net equity issuance by U.S. non-financial corporations turned positive in the first quarter of 2026 - the first time it has done so since the second quarter of 2021. In the firm’s view, rare periods of positive net issuance have tended to coincide with the late stages of major equity booms.
At the centre of the current issuance surge are a handful of very large deals. SpaceX is expected to seek roughly $80 billion in its IPO, which would make it the largest offering on record. Alongside planned listings from Anthropic and OpenAI later this year, the three companies are reported to be targeting a combined raise of about $200 billion - a sum Capital Economics says is sufficient to make 2026 a record year for U.S. initial public offerings.
The firm notes that the proportion of shares likely to be floated initially is relatively small for some of these companies. SpaceX’s public float, for example, is expected to be only about 5% at launch, with similar free float assumptions mooted for Anthropic and OpenAI. However, Capital Economics cautioned that should those free floats expand - to, say, 25% as lockup periods expire - the market could face a very large increase in available equity. The firm estimates such a rise in free floats could amount to an additional roughly $750 billion of equity supply.
Beyond the AI-focused IPOs, Capital Economics also drew attention to activity among the hyperscalers. The firm flagged Alphabet’s reported plan to raise about $80 billion through share sales, and said there are reports Meta may pursue similar transactions as large cloud and AI infrastructure providers look for alternatives to debt-funded capital spending.
Summing up, Capital Economics concluded that recent history suggests a surge in share issuance is often a signal that the close of an equity boom is measured in months rather than years. In the firm’s assessment, gross issuance has tended to peak broadly in tandem with the stock market at the end of the last three major booms.
Contextual note - The observations above are drawn from the firm’s client note and recent issuance data. Where estimates are cited - such as the potential $750 billion figure tied to changes in free floats - they reflect Capital Economics’ calculations based on the assumptions noted in the firm’s analysis.