One man built a product that changed how offices talk. The other built a record that changed how investors pick stocks. At first glance, Stewart Butterfield and Joel Greenblatt have little in common. One lives in the world of software and startups. The other lives in the world of spreadsheets and stock prices.
Yet put them side by side and something useful appears. Wealth usually comes from one of two skills: creating value or recognizing it. Butterfield did the first. Greenblatt mastered the second.
This guide walks through both careers, their biggest wins, and their estimated net worth. You’ll see how their methods differ and what you can borrow from each. One note up front: they aren’t business partners. No joint company or shared deal exists. The pairing works because their paths contrast so sharply.
In this article, you’ll find:
- A full profile of each man, from early life to major wins
- Net worth estimates with the forces behind each figure
- Three clear differences in how they approach business
- Practical lessons for founders and investors
- Quick answers to common questions
Who Is Stewart Butterfield?
Stewart Butterfield is a Canadian entrepreneur best known as the co-founder of Flickr and Slack. Few founders can say they built two products that millions of people used every day. He did it by turning failed games into successful software.
Early Life and Education
Butterfield was born on March 21, 1973, in Lund, a small community on British Columbia’s Sunshine Coast. His family later settled in Victoria. He grew up in an unconventional household, and that independent streak followed him into his career.
He earned a philosophy degree at the University of Victoria. After that, he went to Cambridge for a master’s degree in philosophy. Most tech founders study computer science. Butterfield studied how people think and argue.
Why Philosophy Shaped His Products
Philosophy trains you to ask better questions. It also teaches you to write clearly and to spot weak logic. Butterfield used those skills to study how people communicate. Both Flickr and Slack grew from one big question: how do people share things with each other?
His writing style became a real asset too. His memos were direct and thoughtful. People inside and outside the company read them closely.
Career Timeline
Butterfield’s path looks like a series of pivots. Each one turned a setback into a launchpad.
| Year | Milestone |
|---|---|
| 1990s | Early web design and consulting work |
| 2001 | Co-founds Ludicorp in Vancouver |
| 2004 | Launches Flickr after the game Game Neverending stalls |
| 2005 | Yahoo acquires Flickr |
| 2009 | Founds Tiny Speck |
| 2011 | Launches the online game Glitch |
| 2012 | Shuts down Glitch |
| 2013 | Previews Slack, the internal tool built by the Tiny Speck team |
| 2014 | Slack launches publicly and grows at record speed |
| 2019 | Slack goes public through a direct listing |
| 2021 | Salesforce completes its Slack acquisition |
| 2023 | Butterfield leaves Salesforce |
Stewart Butterfield Net Worth
Stewart Butterfield’s net worth is estimated at roughly $1.5 billion to $2 billion as of 2026. Public estimates vary because they rely on his Slack shares and the final deal price.
Three things drive that figure:
- His Slack stake. As co-founder and CEO, he held a meaningful share of the company’s equity.
- The Salesforce deal. The acquisition valued Slack at about $27.7 billion. That price turned paper wealth into real wealth.
- Earlier exits. The Flickr sale to Yahoo added to his early capital and gave him a base to start again.
Stewart Butterfield’s Major Achievements
Butterfield’s list of wins reads like a startup textbook. Here are the ones that matter most.
- Co-founded Flickr. The site helped define online photo sharing. It also popularized tagging, which let users sort photos by keyword instead of rigid folders.
- Turned a failed game into Slack. When Glitch shut down, his team kept the chat tool they’d built for themselves. That tool became one of the fastest-growing workplace apps ever.
- Took Slack public through a direct listing. In June 2019, Slack skipped the traditional IPO. The company listed on the New York Stock Exchange under the ticker WORK. A direct listing lets existing shareholders sell without the company issuing new shares.
- Sold Slack for about $27.7 billion. Salesforce announced the deal in December 2020 and closed it in 2021. It ranked among the largest software acquisitions of its time.
- Repeated the pivot pattern twice. Game Neverending became Flickr. Glitch became Slack. Few founders pull off even one such turn.
Case study: from a dead game to a billion-dollar tool. Tiny Speck’s team worked in different places and needed a way to talk. They built a messaging system for themselves. It had fast search, clean threads and easy file sharing. When the game failed to find an audience, Butterfield looked at the tool and saw the real product. Within months of its public launch, Slack was adding users at a pace that stunned the industry. The lesson is simple. The best idea sometimes sits inside the worst project.
A line worth remembering: In a famous 2013 memo, Butterfield wrote under the title We Don’t Sell Saddles Here. The point? Customers don’t want the product itself. They want what it lets them do. People bought a better way to work, not a chat app.
Who Is Joel Greenblatt?
Joel Greenblatt is an American investor, author, and teacher. He’s best known for founding Gotham Capital and for creating the Magic Formula, a simple stock-picking method. While Butterfield builds things, Greenblatt studies what existing companies are worth.
Background and Education
Greenblatt was born in 1957. He studied at the Wharton School of the University of Pennsylvania and earned both his undergraduate degree and his MBA there. He started his career in arbitrage and special situations. Those fields reward people who dig into messy corporate events others avoid.
Gotham Capital and the Track Record
In 1985, Greenblatt co-founded Gotham Capital with Robert Goldstein. The firm focused on value investing and special situations. It started small. Early on, the partners managed only a modest pool of money.
The results turned heads. Greenblatt reported returns of roughly 40% a year after fees over about two decades. Those numbers placed Gotham among the best-performing investment firms on Wall Street. Few managers have matched such a long run.
Quick fact: At a 40% annual return, money doubles in about two years. That’s why Greenblatt’s record still gets quoted in investing classrooms.
Later Ventures and Teaching
Greenblatt didn’t stop at one firm. He built several projects that spread his ideas.
- Gotham Asset Management. The firm carried his investing approach forward.
- Value Investors Club. This online community lets investors share and debate stock ideas.
- Formula Investing. A platform that applies his rules to everyday portfolios.
- Columbia Business School. He taught for years as an adjunct professor. His course on value and special situation investing became a campus favorite.
Joel Greenblatt Net Worth
Joel Greenblatt’s net worth is estimated at roughly $500 million to $1 billion as of 2026. Public figures differ because he runs private investment businesses and doesn’t publish exact holdings.
Several sources feed that wealth:
- Investment performance. Decades of strong returns built his capital base.
- Management and performance fees. Gotham’s structure rewards success.
- Book sales. His bestsellers sold widely and kept selling.
- Business stakes. His ownership in Formula Investing and related ventures adds to the total.
Joel Greenblatt’s Major Achievements
Greenblatt’s wins come from results, writing, and education.
- Built a legendary track record. Gotham’s long streak of high returns made his name.
- Wrote You Can Be a Stock Market Genius (1997). The book explains special situations such as spin-offs, mergers, and restructurings in plain English.
- Wrote The Little Book That Beats the Market (2005). This bestseller introduced the Magic Formula to ordinary readers.
- Wrote The Big Secret for the Small Investor (2011). It makes the case for simple, disciplined investing.
- Launched Value Investors Club. The community gave serious investors a place to share research.
- Supported education. He has backed charter school work and taught the next generation of investors.
| Item | Year | What It Did |
|---|---|---|
| Gotham Capital founded | 1985 | Launched his professional track record |
| You Can Be a Stock Market Genius | 1997 | Explained special situations |
| The Little Book That Beats the Market | 2005 | Brought the Magic Formula to the public |
| The Big Secret for the Small Investor | 2011 | Promoted simple, disciplined investing |
The Magic Formula in Plain English
The Magic Formula ranks stocks on two measures. The first is earnings yield, which shows how cheap a company’s profits are compared with its price. The second is return on capital, which shows how well a company turns money into profit. You buy the stocks that rank highest on both.
Greenblatt’s back-tested numbers in the book showed the strategy beating the broader market by a wide margin over many years. Back-tests aren’t live results though. Real-world returns can differ.
Case study: spin-offs. Greenblatt loves spin-offs, where a parent company splits off a division. Big funds often sell the new shares for reasons unrelated to value. Some are forced sellers because the shares don’t fit their mandate. That selling can push prices below fair value. Greenblatt wrote about cases like the 1993 Marriott split, which showed how a patient buyer can profit from other people’s forced decisions.
Stewart Butterfield and Joel Greenblatt: What Connects Them?
Let’s be direct. Stewart Butterfield and Joel Greenblatt have no known business partnership. They haven’t launched a joint company or made a shared deal. They also work in very different fields.
So why compare them? Because the similarities run deeper than the job titles.
What They Share
- Both saw value others missed. Butterfield saw a business inside a failed game. Greenblatt sees mispriced companies that the crowd ignores.
- Both distrust conventional thinking. Neither followed the standard script for their industry.
- Both treat mistakes as part of the process. Butterfield shut down Glitch and moved on. Greenblatt accepts that even great strategies have bad years.
- Both make complex ideas simple. Slack turned messy team communication into one clean workspace. The Magic Formula turned stock analysis into two ranked lists.
- Both share what they know. Butterfield wrote openly about product thinking. Greenblatt teaches and writes for beginners.
One line captures the contrast: Butterfield creates the asset. Greenblatt prices it.
Side-by-Side Comparison
| Category | Stewart Butterfield | Joel Greenblatt |
|---|---|---|
| Field | Software and product building | Value investing |
| Born | 1973 | 1957 |
| Nationality | Canadian | American |
| Main vehicle | Flickr and Slack | Gotham Capital and the Magic Formula |
| Signature win | Slack’s $27.7 billion sale | About 40% annual returns at Gotham |
| Public legacy | Changed workplace communication | Made value investing easy to learn |
| Estimated net worth | About $1.5 billion to $2 billion | About $500 million to $1 billion |
How Their Approaches to Business Differ
Now for the real meat. The two men think about money, risk, and progress in very different ways. Three contrasts stand out. Each one teaches something you can use.
Creating Products Versus Evaluating Businesses
Butterfield starts with a human problem. He asks, “What’s frustrating people?” Then he builds a tool to fix it. His work lives in the world of design, code, and user feedback.
Greenblatt starts with an existing company. He asks, “Is this business worth more than its price?” He doesn’t build anything. He studies what others have built and decides whether the market has it right.
Think of it this way. Butterfield is a chef who invents a new dish. Greenblatt is a food buyer who knows which ingredients are underpriced. Both can make money. They simply work at different ends of the kitchen.
Slack shows Butterfield’s side. It began as a fix for a studio’s messy communication. The Magic Formula shows Greenblatt’s side. It begins with a stock screen and a few ranked numbers.
| Question | Butterfield’s Version | Greenblatt’s Version |
|---|---|---|
| Where do ideas start? | With a user frustration | With a stock price |
| What’s the output? | A product | A portfolio |
| Who’s the customer? | Teams and workers | Investors and clients |
| What counts as insight? | Seeing a need | Seeing a mispricing |
Experimentation Versus Investment Discipline
Butterfield tolerates mess. Early products are rough. Ideas change. He shut down Glitch after the game failed to find enough players, and he didn’t cling to it. Instead, he kept what worked and moved forward.
Greenblatt trusts rules. He picks a method and sticks with it. A good strategy might trail the market for a year or two. He tells investors to hold the line anyway. In his view, switching methods after a bad stretch is how people ruin good plans.
Their approaches to risk look like mirror images:
- Butterfield tests small and pivots fast. He lets the market tell him what works.
- Greenblatt buys cheap and waits. He lets the price do the protecting.
Neither style is better. Product building rewards flexibility. Investing rewards patience. A founder who never pivots may waste years. An investor who always pivots may chase every fad.
Key idea: Experiment when the answer is unknown. Follow rules when the answer is already proven.
Measuring Success
Butterfield tracks signals that show whether people love a product. Those include adoption, retention, and word of mouth. Slack’s growth came from teams that spread it inside their own companies. If users stay and tell friends, the product works.
Greenblatt tracks return on capital and long-run compounding. He asks how much profit a business earns on the money invested in it. For his own portfolio, he judges results over years rather than weeks.
| Measure | Butterfield | Greenblatt |
|---|---|---|
| Main signal | User love and retention | Return on capital |
| Time horizon | Product cycles of several years | Holding periods of a year or longer |
| Warning sign | Users leaving | Price rising above value |
| Win condition | A product people can’t drop | A portfolio that compounds |
Both measure what matters over time. Neither chases short-term noise.
What Entrepreneurs Can Learn From Stewart Butterfield
You don’t need to build the next Slack to use Butterfield’s playbook. Here are the lessons that apply to nearly any founder.
Treat Failure as Raw Material
Game Neverending failed. So did Glitch. Yet both failures produced something better. Flickr and Slack came from tools the teams built along the way. When a project stalls, ask a simple question: “What did we build that people actually liked?”
Solve Your Own Problem First
Slack began as a tool Butterfield’s team needed. They knew the pain firsthand. That gave them a huge advantage. You can test your idea faster when you’re also the customer.
Sweat the Small Details
Slack won on feel. The messages loaded fast. The search worked well. Small touches added up to a product people enjoyed using. Users rarely praise a feature list. They praise how a tool feels at 9 a.m. on a busy Monday.
Know When to Let Go
Butterfield sold Flickr to Yahoo and Slack to Salesforce. He understood that a great exit can beat years of slow growth. Ask yourself whether a bigger partner could take your product further than you can alone.
Write Clearly
His memos showed how clear writing sharpens thinking. If you can’t explain your plan in plain words, you probably don’t understand it yet. Writing forces clarity, and clarity drives better decisions.
Try this: Write a one-page memo about your biggest business problem. State the problem, the options, and your pick. Share it with your team. You’ll spot gaps fast.
What Investors Can Learn From Joel Greenblatt
Greenblatt’s lessons work for beginners and veterans alike. They’re simple on purpose.
Buy Good Businesses at Low Prices
This is the core of his method. He sums it up as buying a good company at a bargain price. A great business at a high price can still be a poor investment. A decent business at a low price often does better.
Stay Patient When the Strategy Lags
Every strategy goes through cold spells. Greenblatt has said that discipline matters even more than the formula itself. Investors who quit after a bad year often miss the recovery. Think of it like a diet. The plan only works if you stay on it.
Look at Special Situations
Spin-offs, mergers, and restructurings create odd price moves. Forced selling and lack of attention can leave real bargains behind. Beginners can study these events and learn how markets sometimes misprice things.
Keep Your Process Simple
A method you can’t follow in a bad year isn’t a method. Greenblatt built the Magic Formula with two measures so that ordinary people could use it. Complexity often hides weak thinking.
Understand What You Own
Even a formula needs judgment. Read about each company before you buy. Know how it makes money. Ask what could go wrong.
| Lesson | What to Do |
|---|---|
| Buy cheap and good | Compare price to profit and quality |
| Be patient | Judge results over years |
| Study special situations | Read about spin-offs and restructurings |
| Stay simple | Use rules you can follow in a downturn |
| Know your holdings | Research before you buy |
Caution: The Magic Formula doesn’t guarantee profits. Past returns don’t predict future ones. This article is for education and isn’t financial advice. Talk with a licensed professional before you invest.
Can Their Careers Offer Lessons for Business Owners and Investors?
Yes. In fact, the biggest gains come when you combine both mindsets. Business owners need to build value. They also need to know what that value is worth. Investors need to judge numbers. They also need to understand how real people use real products.
What Owners Can Borrow From Greenblatt
Many founders track revenue and ignore return on capital. That’s a mistake. Return on capital tells you how well each dollar works inside your business. If you spend $100,000 on a new line and it earns little, that money might do better elsewhere.
Here’s a quick test. List your three biggest spending areas. For each one, estimate the profit it produces. Cut or reduce the weakest. Put more money behind the strongest.
What Investors Can Borrow From Butterfield
Investors often read the numbers and skip the product. Butterfield’s habit of studying real user behavior fills that gap. Before you buy a stock, use the product. Talk to customers. Watch how people react when it breaks or changes.
A company with loyal users and a clear product often has a stronger moat than the spreadsheet shows. Slack’s rise proved that user love can outweigh a big competitor’s marketing budget for years.
One Takeaway for Each Audience
- For business owners: Build something people love and then measure what each dollar returns.
- For investors: Buy quality at a fair price and then check that real customers love the product.
Frequently Asked Questions
Who are Stewart Butterfield and Joel Greenblatt?
Stewart Butterfield co-founded Flickr and Slack. Joel Greenblatt is a value investor behind Gotham Capital and the Magic Formula. One builds products and the other buys businesses.
Are Stewart Butterfield and Joel Greenblatt business partners?
No. Public records show no partnership between them. They work in different fields and built their wealth through separate paths.
What is Stewart Butterfield best known for?
He’s best known for co-founding Flickr and Slack. He also led Slack through its 2019 direct listing and its sale to Salesforce for about $27.7 billion.
What is Joel Greenblatt famous for?
Greenblatt is famous for Gotham Capital’s strong returns, his bestselling books, and the Magic Formula. He also taught value investing at Columbia Business School.
What is the main difference between their careers?
Butterfield creates products from scratch. Greenblatt evaluates existing companies and buys them when the price looks low. One builds value while the other recognizes it.
What can entrepreneurs learn from Stewart Butterfield?
Pivot fast when a project stalls. Solve a real problem you understand. Obsess over small user experience details. Know when selling beats holding on.
What can investors learn from Joel Greenblatt?
Buy good businesses at low prices. Stay disciplined through weak years. Keep your method simple enough to follow when markets turn rough.
Why compare Stewart Butterfield and Joel Greenblatt?
Their careers show two routes to wealth. Butterfield shows how to create value from an idea. Greenblatt shows how to spot value the market has missed.
Conclusion
The story of Stewart Butterfield and Joel Greenblatt comes down to one contrast: build versus evaluate. Butterfield turned failed games into Flickr and Slack. That path led to a net worth estimated between $1.5 billion and $2 billion. Greenblatt turned a simple, rules-based approach into one of the most admired records in investing. His net worth sits in the range of $500 million to $1 billion.
Each man offers a clear takeaway. From Butterfield, learn to treat setbacks as raw material. From Greenblatt, learn to stay patient and let price work for you.
Pick one lesson and use it this week. Write that one-page memo. Or study one company’s return on capital. Small moves, repeated over time, build real results.
