Cassidy, the managing director of RBC Capital Markets' equity research division, said the primary reason for the bank's underperformance was that JPMorgan and Citi's capital markets businesses were extremely strong.
"In particular, the debt underwriting and the FICC trading areas were extremely strong for both JPMorgan and CitiGroup, and of course, Wells Fargo is not in those businesses," Cassidy told CNBC's "Squawk on the Street" on Friday.
FICC trading refers to fixed income, currencies and commodities trading.
Cassidy commented on Sloan's comments Friday morning regarding the future of Wells Fargo's business, calling the tone of the comments "very positive" and "contrite" and saying that the company is "going in the right direction under this new leadership."
While Cassidy said it was difficult to predict what the eventual cost of Wells Fargo's malpractices will be, he said the bank is likely to begin building reserves for payouts over the coming months.