Commercial Banking is the backbone of the modern economy, the familiar institution on your high street or in your banking app. At its heart, a commercial bank is a financial institution that provides services like accepting Deposits, making business and consumer Loans, and offering basic investment products. This is the classic “borrow and lend” business that most people think of when they hear the word “bank.” It's fundamentally different from its swashbuckling cousin, Investment Banking, which focuses on more complex activities like underwriting Initial Public Offerings (IPOs) and advising on Mergers and Acquisitions (M&A). Commercial banks are the workhorses, not the show horses, of the financial world. They facilitate the flow of money by taking in savings from individuals and businesses and lending that money out to others who need it for things like mortgages, car loans, or starting a new venture. This process of credit creation, managed under the system of Fractional Reserve Banking, is essential for economic growth.
Imagine you open a simple grocery store. You buy apples from a farmer for €1 and sell them to customers for €1.50. Your profit is the 50-cent spread. Commercial banks operate on a similar, albeit more complex, principle. Their primary source of income is the Net Interest Margin (NIM). This is the difference between the interest they earn on their Assets (primarily loans to customers) and the interest they pay out on their Liabilities (primarily deposits from customers). For instance, a bank might pay you 1% interest on your savings account but charge a homebuyer 4% interest on their mortgage. The 3% difference is the bank's gross profit on that money. The higher the NIM, the more profitable the bank's core business is. Of course, banks have other ways to make money. They also generate non-interest income from a variety of fees:
For a value investor, a healthy mix of interest income and fee income can signal a stable and diversified business.
Warren Buffett famously said, “Banking is a very good business, unless you do dumb things.” As an investor, your job is to find the banks that aren't doing dumb things. To do this, you need to look beyond the marble columns and friendly tellers and dig into the numbers on the Balance Sheet.
Investing in banks means understanding their unique risks.
Commercial banks can be fantastic long-term investments, but they are not risk-free. Their heavy reliance on leverage means that small mistakes in lending can lead to big losses for shareholders. A value investor should seek out simple, understandable banks with a long history of conservative lending, consistent profitability (good ROA and ROE), and low efficiency ratios. Avoid banks that are growing their loan book too aggressively or operating in exotic markets you don't understand. If a bank's business model and loan portfolio don't fit within your Circle of Competence, it's best to simply look elsewhere.