IEX Group Inc., the year-old dark- pool operator that plans to become a stock exchange, has seen its share of U.S. equity trading hit 1 percent for the first time.

Just over 61 million shares changed hands on the venue yesterday. While that was less than its record of 88 million securities on Oct. 15, yesterday’s overall market volume was 6.1 billion. On IEX’s record day of trading, the wider market had volume of 12 billion shares.

Snagging a full percent of total U.S. trading caps a dramatic year for IEX, which only opened for business on Oct. 25, 2013. The firm was made famous by Michael Lewis’s “Flash Boys” book and an appearance on CBS’s “60 Minutes.” Both portrayed the startup as a bulwark against Wall Street banks and high-frequency traders.

“The next milestone for us is 2 percent,” Brad Katsuyama, IEX’s chief executive officer, said by e-mail. “And given that liquidity begets liquidity, we are hoping it’s a smoother climb than starting from nothing.”

IEX recently raised $75 million from investors including billionaire Steve Wynn and Bain Capital Ventures. The company last month began the process of applying to the Securities and Exchange Commission to gain the status of a stock exchange.

“Our real target for the next 12 months is to get exchange status,” Ronan Ryan, chief strategy officer atIEX, said by phone.