 Investment banking includes financial advisory (mergers and acquisitions, investitures, corporate defense activities, restructuring, and spin-offs) and underwriting (capital raises, public offerings, and private placements of equity and debt instruments).Goldman Sachs is one of the leading M&A advisory firms, often topping the Thomson Financial league tables in sizes of transactions.The firm gained a reputation as a white knight in the mergers and acquisitions sector by advising clients on how to avoid unfriendly hostile takeovers.