On May 10th Uber, the world's biggest ride-hailing firm, listed on the New York Stock Exchange—and promptly tanked.
As The Economist went to press it was trading at $41.29, 8% below its listing price.
On the first day of trading investors lost about $650m. Some have called it the worst initial public offering (IPO) ever.
But it could give a boost to fresh thinking on how fast-growing startups should go public.
And even as Uber's first shares were trading, one such innovation got the go-ahead from
the Securities and Exchange Commission(SEC), America's main financial regulator.
The Long-Term Stock Exchange (LTSE) is based in San Francisco and backed by Silicon Valley luminaries
including Marc Andreessen, Reid Hoffman and Peter Thiel.
They are animated by the weaknesses of conventional exchanges when it comes to startups.
Things such as quarterly results, short-sellers and high-frequency trading distract from building businesses for the long term,
says Eric Ries, the LTSE's boss and the author of "The Lean Startup".
Such distractions are not all unwelcome. Public markets can bring discipline to badly governed startups.
Short-sellers help keep companies honest.
It would probably not have taken them long to sniff out the fraud at Theranos, for instance, had the blood-testing firm been public.
Nevertheless, the LTSE's backers are onto something. Startups have been staying private as long as possible
and granting shares conferring greater voting rights to their founders when they do finally go public.
In turn big private investors, including sovereign-wealth and hedge funds,
have pumped billions into "unicorns" (private firms valued at more than $1bn),
capturing most of the value they create and leaving little for investors in public markets.