> I can equally see a scenario where someone on Facebook or Twitter says "Get out of Wells Fargo" and millions of people would do it.

Who has both 1) an interest in bank balance sheets, and 2) enough clout with Wells Fargo's depositors to cause a SVB-style collapse?

Given how large and diversified Wells Fargo is, I think the only people with the reach to get a message like that out on social media (celebrities) probably don't have the interest or credibility to send such a message and have it listened to.