Investment banks are the financial world's matchmakers. Unlike the commercial bank where you have a checking account, you can't walk into an investment bank to deposit a check or take out a car loan. Their clients are large corporations, governments, and institutional investors like pension funds.

Their main job is to act as an intermediary. They connect organizations that need money to grow or operate with investors who have money to put to work. Think of a company that wants to build a huge new factory but doesn't have the cash on hand. An investment bank helps them raise that money from the public markets.

Investment banks offer several highly specialized services. Most of their work falls into three major categories: Mergers and Acquisitions, Underwriting, and Sales and Trading.

Mergers and Acquisitions (M&A) When one company wants to buy another, or two companies decide to combine into one, they call an investment bank. The M&A advisory team acts like a guide through this incredibly complex process. They help the client figure out how much a company is worth, negotiate the terms of the deal, and handle all the complicated financial arrangements and paperwork. They can advise the buyer (the "buy-side") or the seller (the "sell-side").

Underwriting This is the classic way companies raise large sums of money. Underwriting is the process of creating new stocks or bonds and selling them to investors. The most famous example is an Initial Public Offering (IPO), where a private company sells shares to the public for the first time.

In an underwriting deal, the investment bank typically agrees to buy all the new shares from the company at a set price. They then take on the risk of selling those shares to investors in the market, hopefully for a higher price. The difference is their profit.

Sales and Trading This is the other side of the coin from underwriting. Once securities like stocks and bonds exist, they are bought and sold in the market. The sales and trading division of an investment bank facilitates this.

• Salespeople work with large investors (like mutual funds and hedge funds) to give them ideas and execute trades.
• Traders buy and sell securities on behalf of the bank or its clients, managing the bank's risk and trying to make a profit from market movements.

Investment banks have a very defined and hierarchical structure. This allows for clear lines of responsibility as people advance in their careers. The typical progression in the investment banking division is linear, with each role having distinct duties.

Analysts, typically recent university graduates, do most of the analytical heavy lifting, like building financial models and creating presentation slides. As they get promoted, their responsibilities shift from execution to management and eventually to relationship-building and bringing in new deals at the Managing Director level.

Beyond this hierarchy, banks are also split into different functional areas. The "front office" includes the revenue-generating roles we've discussed: investment banking (M&A, underwriting) and sales & trading. The "middle office" manages risk and ensures compliance with regulations, while the "back office" handles technology, operations, and accounting.

The investment banking landscape is dominated by a few large, global firms, often referred to as "bulge bracket" banks. These are the household names you might recognize.

While these giants handle the largest deals, there are also many specialized "boutique" banks that focus on particular industries (like technology or healthcare) or specific services (like M&A advice only).

Now that you have a foundational understanding of what investment banks do, who they are, and how they're structured, you're ready to explore the more detailed aspects of their operations.