Investing.com — A wave of mega IPOs from SpaceX, Anthropic, and OpenAI, alongside fresh share sales from AI hyperscalers, could pose a significant test for the stock market, according to Capital Economics, which warned that surging equity supply has historically coincided with the late stages of major equity booms.
Markets Economist Joe Maher told clients in a note that gross equity issuance “has tended to pick up markedly during stock market booms,” with the peak of these booms closely coinciding with rare periods of positive net equity issuance in the U.S. Data released this week showed net equity issuance by U.S. non-financial corporations turned positive in the first quarter of 2026 for the first time since the second quarter of 2021.
SpaceX is set to raise approximately $80 billion in its IPO, the largest on record.
Combined with Anthropic and OpenAI, which are expected to list later this year, the three firms are reportedly seeking to raise around $200 billion, “enough to make 2026 a record year for US IPOs.”
Capital Economics noted that only around 5% of SpaceX’s shares will be floated initially, with similar free floats mooted for Anthropic and OpenAI.
If those free floats were to rise to 25%, the firm estimates “that could mean an additional ~$750bn of equity supply” as lockup periods expire.
The firm also flagged Alphabet’s plan to raise $80 billion through share sales, with reports suggesting Meta may follow, as hyperscalers seek alternatives to debt-funded capital spending.
Capital Economics concluded that “recent history suggests surging share issuance tends to be a sign that the end to an equity boom is a matter of months not years away,” noting gross issuance peaked broadly in line with the stock market at the end of the last three major booms.
Related articles
Is the IPO boom a warning sign for stocks?
Wolfe Research outlines eight risks that could spark stock declines in 2026
This sector is ‘poised for a big, beautiful year’: Truist
