| No matter the outcome of the struggle between China and the U.S. over video-sharing app TikTok, an unlikely winner will be a secretive trading firm based outside of Philadelphia. Susquehanna International Group, an options-trading giant, has largely avoided publicity during its three-decade history. Susquehanna’s core business is using quantitative models and computers to execute rapid-fire trades in various markets. Such firms tend to rake in profits by making thousands of small trades a day, often holding securities for fractions of a second. But in the case of TikTok, the firm bet big and held on to its investment for years. | 
