Being a sole trader, I don't have access to CompuStat, Refinitiv, etc. I see a lot of inexpensive fundamentals feeds (e.g. Sharadar, Zacks) that I'd like to use for a quality filter on a momentum trading strategy. Absent the ability to compare these feeds to industry standard sources like CompuStat, what kinds of tests would you run on them to assess quality? Right now my test is to see how they handle big mergers & spinoffs (e.g. movements in the Dow like Alcoa/Arconic/Howmet, HP/HPE, Mondelez/Kraft, Dow/DuPont, UTC/Raytheon). Are there any other "problematic patterns" and test cases that tend to trip up fundamentals data sets?