Shares of the investment management and custodian bank Northern Trust (NASDAQ: NTRS) traded roughly 8.5% lower as of 10:36 a.m. ET today after the bank reported earnings results for the first quarter of the year. In the quarter, the bank saw its largest revenue source -- trust, investment, and other servicing fees -- fall 9% year over year, although this line item was up 2% from the sequential quarter. Total assets under custody and administration rose 4% from the sequential quarter but were still down 9% year over year.