HONG KONG — Global investors in two weeks will get direct access for the first time to the stock market in the Chinese city of Shenzhen, giving them a chance to bet on a tech-heavy clutch of private companies on an exchange sometimes called China’s Nasdaq.

But many investors will be skeptical, and the tale of Baofeng Group explains why.

A largely unknown tech firm that designs online video players, Baofeng conducted a modest debut on the Shenzhen exchange in March 2015. Over the next three months, its stock rose 4,200 percent.

The company went public at the height of China’s share market frenzy, as speculative investment in stocks became the national hobby. Vast fortunes were minted — Baofeng’s chief executive became a billionaire almost overnight.

Then, just as quickly, investors’ hopes were dashed. Chinese stocks imploded in June of that year. The government’s attempt to stem the losses with trading suspensions, bans on selling and a campaign of state-directed buying only added to the concerns of private investors.