Complex sentence: At the time, brokers crowded around a glass dome-topped ticker tape which printed out the latest stock results, provided by telegraph, or wire service, from Western Union, and those who were closest gained the advantage.
Split into simpler sentences: At the time, brokers crowded around a glass dome-topped ticker tape which printed out the latest stock results. This information was provided by telegraph, or wire service, from Western Union, and those who were closest to the tape gained the advantage.