How low can it go? For starters, Wells Fargo stands to lose $99Bn in deposits, $4Bn in revenue, and 30% of its customer base, according to a study by cg42. While most of the respondents said they had not been directly affected by the accounts scandal, the "breach of trust the scandal created has fundamentally changed the way that they think about their institution, the way they think about the bank." 

In its survey, cg42 asked 1,000 primary Wells Fargo customers and another 500 primary customers of other top 10 banks what they thought of the scandal and whether it would change their behavior. Among other things, cg42 studies what its founder, Steve Beck calls "brand vulnerability," to public perception and its studies are often cited in media reports on industry trends.

One of the more interesting things the firm has found about Wells Fargo is that customer concerns over cross-selling didn't just start when the scandal broke in September.  "Dating back to 2011, customers have consistently over-indexed on the frustration of being sold products I don't need or want," Beck said. "What the scandal has brought to life is that that wasn't just solely based on a culture that pushed for cross-selling and upselling. But it went further than that."

The study also found that before the scandal, 60% of respondents had a positive impression of the bank. Afterward, that number dropped to just 24%. Negative brand perceptions increased from 15% to 52%.