Same error/problem for me. I'm running Windows 10; Google Chrome (Version 68.0.3440.106 (Official Build) (32-bit). Frontier Internet provider. The page that shows MY stocks works: I can even buy shares from companies I already have stocks in from that page. However, if I try to toggle back and go to all stocks, I get the 500 Error page with no other info provided on the page or from my browser.
Also, I don't know if it's relevant, but Torn stats award tracker is a little off - it shows percentage progress, but it's no longer showing when something is "Completed". Also, my DocTorn isn't connecting.
Same issue here. For myself, when accessing the stock market page (from flying using the TC laptop) bounces back to the flying page after a few seconds. Also identical issue with the Torn App.