The Chart Munger Kept Coming Back To
Charlie Munger once said you could tell a lot about a business just by looking at its Value Line chart. Not the 10-K. Not the earnings call transcript. Not the sell-side research. The chart.
He wasn't talking about technical analysis — moving averages, head-and-shoulders patterns, and the rest of the chartist religion. He meant something entirely different. Value Line published a very specific kind of chart: price and earnings plotted together on a logarithmic scale, going back fifteen years or more. And Munger, who spent more time thinking about compounding than almost anyone who ever lived, understood why that particular chart told you nearly everything you needed to know.
Why logarithmic
Most stock charts use a linear scale. A move from $10 to $20 looks the same height as a move from $100 to $110. Both are $10. But the first is a 100% return. The second is 10%. On a linear chart, those two very different outcomes look identical.
A logarithmic scale fixes this. On a log scale, equal vertical distances represent equal percentage changes. A doubling from $10 to $20 takes up exactly the same space as a doubling from $100 to $200. This means a stock compounding at a steady rate shows up as a straight line. Not a curve that gets steeper and steeper — a straight line.
Think about what that means. Compounding — the most powerful force in investing — becomes visible. You can literally see it. A business compounding earnings at 15% per year for two decades shows up as a clean, ascending line at a consistent slope. A business whose growth is decelerating shows a line that's bending over. A business that's accelerating shows a line steepening. All of this is immediately apparent on a log chart and completely hidden on a linear one.
Munger and Buffett built Berkshire Hathaway on the back of compounding. They weren't traders looking for the next catalyst. They wanted to identify businesses that could compound capital at high rates for very long periods — and then hold them. The log-scaled chart was their visual confirmation. If the chart looked like a straight line going up and to the right, the business was doing what they needed it to do.
What Value Line got right
Value Line Investment Survey, first published in 1931, was a remarkable product. For decades, it was the go-to reference for serious individual investors. Each stock got a single page — a one-page tearsheet — with a chart at the top and key financial data below.
The chart plotted stock price as a solid line, with earnings overlaid as a shaded area, both on a log scale. Fifteen years of data. At a glance, you could see:
- Is this business compounding? A rising price line on a log scale means consistent percentage growth, not just nominal growth. The slope tells you the rate.
- Are earnings driving the price, or is speculation? If price and earnings move together, the market is pricing the stock rationally based on fundamentals. If price detaches from earnings and runs ahead, the market is paying for hope.
- Is the stock cheap or expensive relative to its own history? When the price line sits above the earnings line by more than usual, the stock is expensive. When it sits below or right on top, you're getting earnings at a reasonable price.
Three questions. One chart. Fifteen seconds.
Munger didn't need sophisticated models. He needed to see the pattern. The log-scaled chart was the pattern. A compounder looks like a compounder. A cyclical looks like a cyclical. A declining business looks like a declining business. And a stock that's gotten ahead of its fundamentals looks exactly like that, too.
What gets lost on a linear chart
Consider a company that grew earnings from $1 to $16 per share over twenty years. On a linear chart, the early years look flat — the move from $1 to $2 barely registers. The later years look explosive — the move from $8 to $16 dominates the chart. It looks like the business accelerated dramatically. But it didn't. It compounded at the same rate the entire time. Around 15% a year, steadily.
Now look at the same company on a log scale. The line is straight. Perfectly consistent. You see the truth: this is a steady compounder, not a recent rocket. That distinction matters enormously when you're trying to decide whether growth is sustainable.
Linear charts also distort comparisons. If you're comparing a $20 stock to a $200 stock, the $200 stock's moves look ten times larger on a linear chart even if the percentage moves are identical. On a log chart, equal percentage performance looks equal, regardless of share price. You're comparing like with like.
How we use this
On every stock page on The Ledger Terminal, the valuation chart uses a logarithmic scale on both axes. This isn't a default we picked casually. It's a deliberate choice rooted in how Munger and the Value Line tradition thought about visualizing business quality.
The chart plots four layers of information:
Stock price — the actual market price, plotted as a solid line. On the log scale, a steady compounder appears as a clean upward slope. You can eyeball the growth rate from the angle.
Fair value — a dashed teal line representing what the stock would be worth at its historical median valuation multiple applied to trailing fundamentals. This is the equivalent of Value Line's earnings overlay. When price runs above fair value, you're paying a premium. When it dips below, you may have an opportunity.
Earnings histogram — bar charts showing the actual per-share fundamentals (EPS, free cash flow, cash flow, or owner earnings, depending on which method you've selected). This is the engine. If the bars are growing, the business is compounding. If they're flat or shrinking, no amount of multiple expansion will save you.
Relative strength — a dotted line showing how the stock has performed versus the S&P 500. A stock compounding faster than the index will show a rising line; one lagging will show a declining line.
You can switch between four valuation methods — P/E, P/FCF, P/CF, and P/OE (owner earnings, Buffett's preferred measure) — to see the picture through different lenses. Each tells a slightly different story, and the divergences between them are often where the insight hides.
The Munger test
Here's how Munger would have used a chart like this — and how you can too:
Step one: look at the slope. On the log scale, is the price line rising at a consistent angle? If yes, you're looking at a compounder. The steeper the angle, the faster the compounding rate. A business that's been compounding at 12-15% annually for a decade has a very particular look. Once you've seen enough of them, you start recognizing quality businesses instantly.
Step two: look at the gap. Is the price line close to the fair value line, or has it separated? A wide gap above fair value means the market is enthusiastic — possibly too enthusiastic. A price sitting at or below fair value after years of steady earnings growth is exactly the situation Munger spent his career looking for.
Step three: look at the earnings bars. Are they growing? Steadily? The bars are the fundamentals. The price line is what the market thinks about the fundamentals. Ultimately, the bars win. If the bars are growing, the price follows — eventually. If the bars stop growing, the price finds out — eventually.
This entire assessment takes less than thirty seconds. You're not running a DCF model. You're not building a spreadsheet. You're doing what Munger did: looking at the shape of a business and deciding whether it deserves more of your time.
Most stocks fail the test
That's the point. The log-scaled chart is as useful for what it eliminates as for what it highlights. Most businesses don't compound. Their log-scale charts look jagged, flat, or downward-sloping. They might have a good year here and there, but the overall pattern is noise, not signal.
Munger famously said his approach to investing was "Sit on your ass. Read a lot." The chart was the first filter. If the chart didn't show a compounder, he moved on. No meeting. No model. No further analysis. Life is too short to spend it on mediocre businesses.
When you find one that passes — a clean upward slope on the log scale, earnings growing in lockstep, the price sitting at or near fair value — that's when you open the financial table and start doing the deeper work. The chart tells you where to look. The numbers tell you whether to buy.
That's what Munger understood, and it's why he kept coming back to that chart.