Secondary trading in shares of hot startups making a strong comeback

San Francisco

AFTER the debacle that preceded the initial public offering of Facebook Inc in 2012, when the company's stock changed hands at wildly varying prices and with little oversight, the market in secondary trading in shares of hot startups has made a strong comeback.

Regulators and the startups themselves have gradually tightened rules governing buying and selling shares, while a growing number of startups delaying their IPOs amid a wash of eager private capital has created a huge swell of demand among both buyers and sellers.

"A lot of companies learned from the headaches that Facebook …