Jeremy Grantham, co-founder and chief investment strategist of GMO LLC, during an interview on an episode of Bloomberg Wealth with David Rubenstein in Boston, Massachusetts, US, on Thursday, Aug. 17, 2023. Grantham started one of the world’s first index funds in the early 1970s and in 2011 he was included in the 50 Most Influential ranking of Bloomberg Markets magazine. Photographer: Vanessa Leroy/Bloomberg
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Jeremy Grantham went on CNBC and said his Bitcoin prediction was that it would eventually “dwindle away with a whimper.” Joe Kernen pushed back, the conversation became personal, and the clip quickly traveled across the internet.
That is hardly surprising. Put Jeremy Grantham, Bitcoin, CNBC, a prediction of zero and two strong personalities in the same conversation, and the internet will do the rest. I watched the exchange differently. I was less interested in whether Grantham likes Bitcoin than in whether his prediction was remotely useful to an investor.
He may ultimately be right. Bitcoin may gradually lose relevance, collapse in value, or become a historical reminder of what can happen when speculation, liquidity, and collective belief meet at the same time. Grantham has spent decades studying bubbles, and dismissing his argument simply because you own Bitcoin would be foolish. But when the timeframe is “years and years, decades and decades,” we are no longer talking about an investment call. We are discussing an opinion that can remain technically alive for the rest of someone’s career.
I have spent over 30 years in markets, and “eventually” is one of the most expensive words in investing. You can be completely right about the destination and still lose a fortune on the journey. A bubble can grow larger. An expensive asset can become pricier. A poor business can survive much longer than expected, and a speculative asset can continue attracting capital long after intelligent people have declared it finished.
That is the problem with dramatic predictions. They make excellent television because they sound decisive. Portfolios require something much harder: a valuation, a catalyst, a timeframe, a sensible position size and an honest understanding of what would prove the thesis wrong.
Grantham’s Bitcoin Prediction Has No Expiry Date
Every speculative boom eventually ends. The difficulty lies in knowing when to sell, how to sell, and at what price to sell. An investor who correctly identifies a bubble five years early may still lose more money than the investor who never recognized it at all. A stock believed to be worth $20 can trade at $50, then $100, before the market finally agrees. A short seller can be fundamentally right and still end up financially ruined if they time it wrong. Timing is a major aspect of an investment thesis. It is part of the thesis. Grantham’s argument allows Bitcoin to decline over decades. That may eventually make the prediction look remarkably perceptive, but it offers almost no guidance to an investor today.
Should Bitcoin be shorted now? If so, how large should the position be? What happens if it doubles first? Would a move to a new high invalidate the argument or merely make the bubble larger? How long should an investor continue funding the position while waiting for the eventual whimper? Those are not technical questions. They determine whether the view can be turned into an actual return. Bitcoin could ultimately disappear and still rise substantially before it does. It could remain volatile, divisive, and difficult to value for decades while attracting institutional investors, governments, and individuals who see it as an alternative monetary asset.
Saying that something eventually goes to zero is easy. The challenge is surviving everything it does before reaching zero.
A Bitcoin Prediction Is Not an Investment Thesis
The investment industry often confuses a memorable opinion with an investable idea, but they are not the same. They are not the same thing. An investable thesis should explain what is mispriced, why the market is wrong, what changes next, and how long that change may take. It should identify the catalyst and the major risks. Most importantly, it should explain what evidence would show that the original analysis has failed. A prediction can avoid all of that. It can remain open indefinitely, which makes it almost impossible to disprove. That is why forecasts work so well on television. The audience remembers the destination but rarely audits the journey. Someone predicts a market crash, the market rises for another five years, and then eventually declines, and the original forecast is presented as a remarkable call.
But what happened to the investor who acted five years earlier? Suppose you agree entirely with Grantham and believe Bitcoin will eventually be worth nothing. How do you profit from that belief? Shorting it exposes you to an asset capable of violent upward moves. Buying put options forces you to choose an expiry date, which is precisely what the original prediction avoids. Refusing to own Bitcoin may be a perfectly sensible portfolio decision, but avoiding an asset is not the same as generating a return from its collapse. You can therefore be philosophically correct and financially unrewarded.
This distinction applies far beyond Bitcoin. Investors have spent years predicting the demise of expensive technology stocks, housing markets, government bonds, currencies, and entire industries. Some of those predictions were directionally correct. Many were too early, too vague, or too difficult to implement to create any value. Markets do not pay for eventual intellectual vindication. They pay investors who identify a mispricing and express it in a way that can survive until the thesis works.
Why This Bitcoin Prediction Makes Great Television
The Grantham–Kernen exchange is spreading because it was not a dry conversation about valuation. It became a confrontation. Grantham represented the traditional bubble investor: skeptical of an asset that produces no earnings, pays no dividend, and generates no free cash flow. Kernen represented the other side: investors who believe that traditional valuation methods cannot dismiss Bitcoin’s scarcity, network, and challenge to conventional money. Both sides believe the other is missing something obvious.
That creates excellent television and even better social media. People are not only debating Bitcoin. They are defending identities, generations, and competing ideas about what money and value actually mean. The strongest media moments reduce complicated issues to opposing camps. Bitcoin is either digital gold or worthless. Grantham is either a wise veteran warning investors again or a permanent bear who fails to understand a new financial system. Real investing is rarely that clean.
I do not need to decide that Bitcoin is either the future of money or destined for zero. I need to decide whether the expected return justifies the risk at the price available today. That is a less dramatic question, but it is the one that matters. The absence of traditional cash flow makes Bitcoin difficult to value, but difficulty does not remove the need for discipline. It increases it. Position size, entry price, liquidity, and the ability to withstand volatility become increasingly important. An investor does not need to accept Grantham’s final conclusion to recognize the risks. Equally, an investor does not need to believe in Bitcoin to understand that aggressively betting against it could be disastrous.
The Better Question Behind Grantham’s Bitcoin Prediction
Grantham may eventually be proven right. His criticism of Bitcoin’s utility, volatility, and lack of traditional intrinsic value deserves serious consideration. But the more useful question is not whether Bitcoin will still exist in several decades. The more useful question is what the current price assumes, what could change those assumptions, and whether the likely return compensates investors for the risks. That is the same process I apply to stocks, spinoffs, restructurings, and activist situations. What is the asset worth? Why might the market be wrong? What is the catalyst? Who or what controls the outcome? How much time does the thesis require, and what would show that it is failing? Those questions turn an opinion into a process.
The market loves bold predictions because they produce heroes and villains. Investors should focus on whether they can translate the prediction into a position they can afford to hold. Grantham may be right about the eventual destination. But being right about where something ends means little if you cannot explain what happens next or survive the path required to reach that destination.
The Bitcoin prediction of “Eventually” provides none of them.