As the high-speed trading industry endures a wrenching period of consolidation, Two Sigma Securities is looking to come out on top.

The secretive firm, an affiliate of the $45 billion quantitative hedge fund Two Sigma Investments, said this week it had agreed to buy the global options market-making business of Interactive Brokers Group Inc., which helped pioneer electronic trading in the 1980s.

The deal is designed to push Two Sigma Securities—a relative upstart founded in 2009—into the big leagues, alongside global giants such as Citadel Securities LLC, which account for a huge portion of trading activity in the U.S. and overseas.

“Over time, I see us expanding into other asset classes and other geographies,” Two Sigma Securities Chief Executive Officer Simon Yates told The Wall Street Journal.

Scale has grown more important for high-speed trading firms as the industry struggles with unfavorable market conditions, especially low volatility, which reduces their ability to profit from price swings. The revenues of such firms from U.S. equities trading were an estimated $1.1 billion last year, down from $7.2 billion in 2009, according to research firm Tabb Group.