The Yahoo app is still carrying the stock prices and changes from Thursday's close, even after Friday's plummeting markets. Very bad!
While the web data is accurate, the app (at least on Android) is not. So, either you have a separate feed that is consumed by the mobile app, or there are bugs in your feed. I've seen this before but the hugs drop in Friday's markets made it really stand out. While stocks dropped precipitously, all the stocks I track are still showing Thursdays prices, with their gains (all green) from that day. Friday's prices are just not there. Fix your feeds. Perhaps using Kafka to perform real-time audits of data would be helpful.
Steven Roth commented
The word "hugs" should be "huge". Your website didn't allow me to edit the post. It only gave me the option to delete it. That tells me that there's a bug in your website.