European repo grew from €169.4 billion in July 2016 to €228 billion at the end of July 2017.
Nex Group also beat its June 2017 EU repo volume by 4 percent, which previously stood at €220 billion.
The group also experienced a 7 percent change in its US market. The figure rose from $212 billion to $225.2 billion from July 2016 to July 2017.
Volume information includes US treasury benchmarks and agencies, as well as off-the-run securities, including treasury bills.
According to NEX Group, geopolitical events, such as the US presidential election and Brexit result in June last year were the most significant drivers of fixed income trading over the past 12 months.
Michael Spencer, CEO of NEX Group, said: “Our performance remains strong in a tough market environment. NEX Markets has focused on expanding its product suite to a wider client base and continues to win market share in EU repo.”