Wells Fargo reported a decline in its second-quarter profit due to increased costs to retain deposits amid intense competition for customers' money. The bank's net interest income, a key measure of income from lending, fell by 9% year-over-year to $11.9 billion. This shortfall led to a 6% drop in Wells Fargo's shares, including a 5.5% decline in pre-market trading. The bank also warned that it would not be able to reduce costs as quickly as previously anticipated, following higher-than-expected expenses in the second quarter. Additionally, overall deposits at Wells Fargo dropped, reflecting broader challenges faced by major banks in the current economic environment.