It's a nice start, but AI isn't delivering that much as of now, human experience and filtering is needed to grab sentiment, and even that can be a subjective judgement, based on your own emotion for that particular timeframe for example.
Did you look at some of the tweets that are counting toward that fail? Some of the are "HSBC sucks" variety, but many were about HSBC providing bad economic news or were actually neutral. Not sure exactly how they're doing the pass/fail, but it looks like it's time for a review. How a tweet saying that HSBC dominates as the biggest mortgage lender gets marked "fail" I don't get.
(Not denying your argument, but there's layers here, onion girl. :-)
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