Wells Fargo's second-quarter profit dipped due to higher deposit costs, causing the lender to miss analysts' estimates for net interest income. The bank's shares fell more than 6% as NII decreased by 9% to $11.92 billion. Wells Fargo expects NII to slide by 7% to 9% this year. The bank is facing fierce competition for customers' money, forcing them to pay more to retain deposits. Wells Fargo's profit beat expectations in Q2, with a boost in fees from investment banking helping to offset the decline in NII. Despite challenges, investment banking revenue surged 38% to $430 million. The bank is looking to grow its investment banking and trading activities under CEO Charlie Scharf, despite constraints from a $1.95 trillion asset cap and ongoing regulatory issues.