When Bank of New York Mellon reported fourth-quarter earnings yesterday, its slight miss on earnings caused a drop in its stock value. But it wasn't alone. State Street 's shares also took a hit, because investors know that similar pressures are facing both big custody banks. Yesterday's headwinds turned into a breath of fresh air today, however, as State Street delivered sparkly Q4 results, and a promise of more expense-side savings for the coming year. Finishing up the year in good shape State Street had lots of good news wrapped up in its report, such as a 6% hike in revenues year over year, and a 19% gain in adjusted earnings per share. Net interest revenue increased somewhat from last year, while the important net interest margin (on an adjusted basis) decreased only slightly from last year - by four basis points - compared with fellow BNY Mellon, which presided over a NIM drop of 18 bps.