Every era of tech has its defining IPOs. From the dawn of the PC (Microsoft, 1986) and the Web revolution (Netscape, 1995) to the rise of the Faangs (Google, 2004) and China's new tech champions (Alibaba, 2014), these stock market debuts have been emblematic of their times.

Tech's unicorn era is finally having its Wall Street moment — and it is not pretty.

WeWork's biggest backer, SoftBank, wants to call a halt to a planned listing, while Uber's shares stumbled to a new low last week, about a third below their IPO price.


These have been the two biggest