A leadership fight has broken out over one of the world’s most secretive and profitable high-frequency trading firms, pitting a beret-wearing mathematician against a former business partner and a Ukrainian physicist.

The dispute in recent weeks has spilled into lawsuits that, for the first time, shed light on the inner workings of Quantlab Financial, a Houston-based high-frequency trading firm. A website for co-founder Wilbur “Ed” Bosarge Jr. says the firm accounts for between 3% and 10% of total daily volume on the venues where it trades.