I’ve spent years in the markets and I’ve seen many investors make the same mistake: confusing the nominal value and the true economic value of shares as if they were the same thing. They are not. In fact, understanding the difference between these three concepts—nominal value, book value, and market price—is what separates those who lose money from those who truly make gains.

Today I want to share what I’ve learned about how to interpret each of these values and when to apply them in the real world. Because here’s the detail: each one tells a different story about the same stock.

Let’s start with the basics. The nominal value of a share is simple to calculate, but many people don’t understand what it actually represents. It’s obtained by dividing the company’s share capital by the total number of shares issued. Imagine a company going public with 6,500,000 euros in capital and issuing 500,000 shares. The nominal value would be 13 euros per share. Simple, right? But here’s what matters: that nominal value is practically irrelevant after the first day of trading. It’s just a starting point—nothing more. In equities, it’s rarely used.

The interesting part starts when we look at book value. This one does have real utility. It’s calculated by taking the company’s assets, subtracting liabilities, and dividing the result by the shares issued. Let’s look at a practical example: a company with 7,500,000 euros in assets and 2,410,000 in liabilities, with 580,000 shares issued, would have a book value of approximately 8.77 euros per share. This number tells you something crucial: what’s really on the company’s books.

Now, that book value is where many value investors like me pay attention. Warren Buffett popularized this obsession with finding companies with strong balance sheets at attractive prices. The logic is simple: if the market price is below the book value, you’re potentially buying the company cheaper than it should cost. But here’s the important nuance—this works well for banks, insurance companies, and traditional businesses. For tech companies and small caps, it creates many inefficiencies. Book value is not the absolute truth.

And then there’s market value—the price you see on your screen when you open any trading platform. This is the one that really matters when you’re trading. It’s calculated by dividing market capitalization by the shares issued. A company with a market cap of 6,940 million and 3,020,000 shares would have a market value of approximately 2.30 euros. But here’s the fascinating part: that price doesn’t tell you whether it’s expensive or cheap. It only tells you what it is, not what it should be.

The difference between nominal value and the true economic value of shares is where many people lose perspective. Nominal value is historical—almost irrelevant. The true economic value—the one that really matters—is a combination of what accounting says (book value) and what the market is willing to pay (market value). You need both to make smart decisions.

In practice, I use these values in very specific ways. With book value, I compare companies in the same sector using the Price/Book ratio. If one gas company trades at 0.6 times its book value and another at 0.8, the first is relatively cheaper. But that doesn’t mean I should buy the first one—I still need to verify business quality, profitability, and trends. The ratio is just one tool among many.

Market value is my constant reference. When I set a take-profit, I do it based on price. When I place a limit buy order expecting a dip, I use the market price as my reference. Trading hours matter here: Europe trades from 9:00 to 17:30, the United States from 15:30 to 22:00 (Spanish time), and Asia in the early morning. Outside these hours, I can only leave pre-set orders.

But each method has its traps. Nominal value is practically useless after issuance, except in special cases like convertible bonds, where it sets a future conversion price. Book value takes a hit when companies have lots of intangible assets or when they use accounting tricks—creative accounting is real. And market value is constantly distorted by factors that have little to do with the company’s financial reality.

Look, I’ve seen stocks revalue irrationally because the sector was in euphoria. I’ve seen brutal declines caused by changes in monetary policy that had nothing to do with the company. The market discounts future expectations, yes, but it also overinterprets news, reacts to rumors, and sometimes simply gets it wrong. That’s why market value is deeply volatile and inherently uncertain.

So how do you put all of this together? Nominal value and the true economic value of shares are concepts you need to understand together. Nominal is your historical reference point. True economic value is what the market pays today. And in between is book value, telling you what’s actually in the books. If the market price is far above the book value, you might be overpaying. If it’s far below, there may be an opportunity. But that’s only the first filter.

Don’t fall into the trap of obsessing over a single ratio or method. I’ve seen people look only at P/VC and lose money because they ignored that the company was in decline. I’ve seen others obsess over nominal value in equities, which is almost useless. Investing requires context, multiple forms of analysis, and the correct interpretation of the data.

In conclusion, understand that nominal value is the historical starting point. Book value shows you financial health according to the books. And market value is what you actually pay. You need all three to make informed decisions, but each one at the right time and in the correct context. The difference between nominal value and the true economic value of shares is fundamental, but real mastery lies in knowing when to use each one.