The volume of data, and the required speed of transmission to stay more-or-less current with the actual market conditions outstripped the capability of 'tape' printers.
Just as _telegram_ printing shifted to roll-feed wide paper, from the tape, what remained for dedicated mechanical printers did similarly.
In the 60s, early-70s ...
Bunker-Ramo came out with electronic quote display terminals, and practically owned the _broker_ market for a number of years.
Telerate also came out with a CRT display supporting many, _many_ 'pages' of display data -- everything from news stories to lists of latest market prices -- either as groups displayed simultaneously on a single 'page', or single issues as a streaming 'ticker' across the bottom of the screen.