july 14 reuters  citigroups cn profit tumbled 36 in the second quarter as weakness in the wall street banks trading business blunted gains from its personal banking and wealth management unit wall street traders have hit a rough patch joining investment bankers whose businesses have been weighed down for months by a slump in dealmaking citis markets revenue fell 13 to 46 billion on more subdued activity in fixed income and equities while its investment banking fees plunged 24 to 612 million net income sank to 292 billion or 133 per share in the three months to june 30 the bank reported on friday that compares with 455 billion or 219 per share a year earlier