Companies' race to issue shares reminds analysts of prior rally peaks. SpaceX's record $75 billion public offering, Alphabet's $85 billion equity raise, and a $26 billion-plus ADR sale from South Korean chipmaker SK Hynix highlight the frenzy.

Investors have cheered a bull market lasting three years and nine months, with the S&P 500 more than doubling. Now firms rush to capitalize, raising fears the rally may be nearing its end. Markets don't collapse from age alone, but new issuance can overwhelm demand.

In late 1999 and early 2000, heavy share sales contributed to the dot-com collapse. This year, $344.7 billion in new shares have been sold—exceeding full-year totals for 2022-2025, per Dealogic. Buybacks are also slowing.

"Stock issuance tends to surge in the late stages of a bull market," says Rob Arnott**, chair of Research Affiliates, underscoring why some investors are wary.