how do you recognise a bubble while you are in one

You mostly cannot date it, but the pattern is recognisable: valuations disconnected from earnings, new participants arriving in large numbers, leverage rising across the system, sceptics dismissed rather than answered, ordinary conversation turning to markets, and a story explaining why it is different this time. From inside, every one of these reads as confirmation — the sceptics have been wrong for two years and the participants keep being proved right in real money. None of the signals marks the top, which is why the workable responses are mechanical rather than predictive.

in a bubble most of the eventual loss comes from

The multiple contracting, not the business failing. A share bought at 90 times earnings on the assumption of 45% growth can fall roughly 45% when growth normalises to a still-excellent 22% and the multiple settles nearer 35 times — while the company grows revenue every single year. That is why “but the business is good” is not a defence: the loss came from the price the story was bought at.

why is “it is different this time” so hard to argue against

Because it is usually partly true — bubbles are built on stories that are genuinely accurate. The internet really did change everything, and India’s formalisation is real; what fails is the price paid for the story in advance, not the story itself. Waiting for the narrative to be disproved is waiting for the wrong thing, and reflexively calling every new development a bubble is its own expensive error.

what do people actually do when they think prices have run too far

The responses that hold up are mechanical rather than predictive: rebalancing back to a target allocation on a fixed date instead of on a view, and not adding leverage. Rebalancing reduces equity exposure automatically as prices rise without requiring anyone to call a top, and bubbles rarely ruin people who are unleveraged. Writing down in advance what would change your mind matters too, because later you will have reasons for everything and they will all point where the market has been moving.

can you short a bubble

You can, and it is the response with by far the worst risk profile, because being right about a bubble and early is indistinguishable from being wrong. The position is usually closed at a loss long before the thesis pays, and losses on a short are not capped the way losses on a holding are — the price of what you sold can keep rising. Reducing exposure costs you some upside if the run continues; the asymmetry is the whole reason the two are not comparable choices.

What a bubble feels like from inside

Everyone believes they would recognise a bubble. Almost nobody does, because from inside one the evidence points the other way: the sceptics have been wrong for two years, the participants have been right repeatedly, and their gains are real money in real accounts.

Think of it like this

Party se jaldi nikalna

Leaving a party early always feels like a mistake at the time. Everyone is still there, it is still fun, and you are the one being boring. It only looks sensible the next morning, and by then nobody remembers who left when.

In the market

Reducing risk in a bubble feels exactly like this. You underperform visibly, for months, in front of people who are doing well — and there is no moment at which the room agrees it is time to go.

What the pattern actually looks like

Signal	What it sounds like at the time
Valuations disconnected from earnings	“The old metrics do not apply to this”
New participants in large numbers	“Everyone is finally waking up to it”
Leverage rising across the system	“Money is cheap, it would be foolish not to”
Sceptics dismissed rather than answered	“They have missed the whole move”
Ordinary conversation turns to markets	“Even my barber is invested” — said approvingly
A story explaining why it is different	The story is usually partly true, which is what makes it work

Why "it is different this time" is hard to dismiss

Because sometimes it is. Dismissing every new development as a bubble is its own error, and people who did that missed decades of genuine change. The useful question is never whether the story is true — it is what price the story is being sold at.

Worked example

A true story at the wrong price

A company growing revenue 45% a year

The storyThe market is real, the growth is realEntirely accurate

Price paidAssumes 45% growth continues for many years90× earnings

What actually happenedStill excellent by any normal standardGrowth slowed to 22%

What the multiple didStill a premium multiple90× → 35×

The share priceWhile the business grew every single yearDown roughly 45%

Nothing about the story was wrong. The company grew throughout. The loss came entirely from the price at which the story was bought — which is what bubbles are, and why "but the business is good" is not a defence.

Loading interactive demo…

Adjust growth and the multiple independently. Most bubble losses come from the multiple contracting, not from the business failing.

What to actually do

Four responses, none of which is "call the top"

1
Rebalance mechanically
Sell back to your target allocation on a date, not on a view. This reduces exposure automatically as prices rise, without requiring you to predict anything.
2
Stop adding leverage
The single most consequential decision. Bubbles do not ruin people who are unleveraged — they ruin people who borrowed near the end.
3
Write down what would change your mind
Do it while you are calm. Later you will have reasons for everything, and they will all point in the direction the market has been moving.
4
Accept underperforming visibly
You will look wrong for a long time, in front of people. There is no version of prudence that avoids this, which is precisely why so few people manage it.

Check yourself

A company grows revenue every year for four years, yet its share price falls 45% over the same period. What most likely happened?

Simple bhasha mein

Party se jaldi nikalna

Party se jaldi nikalna hamesha galat lagta hai — sab abhi bhi wahin hain, maza aa raha hai, aur boring aap ho. Sahi sirf agli subah lagta hai. Bubble mein risk kam karna bilkul yahi hai: aap mahino tak sabke saamne galat dikhoge, aur nikalne ka koi ghanta nahi bajta.

What to remember

From inside a bubble the evidence points the wrong way — participants keep being proved right.
Bubbles are built on stories that are genuinely true; the error is the price, not the story.
Most losses come from the multiple contracting while the business keeps growing.
Rebalance mechanically and stop adding leverage rather than trying to call the top.
Do not short it — being early is indistinguishable from being wrong.

You reached the endMark it done and keep your streak going.

Up nextWhen the income stops Previous: The lines worth not crossing

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Common questions

Short, direct answers to what people ask about this topic.

how do you recognise a bubble while you are in one: You mostly cannot date it, but the pattern is recognisable: valuations disconnected from earnings, new participants arriving in large numbers, leverage rising across the system, sceptics dismissed rather than answered, ordinary conversation turning to markets, and a story explaining why it is different this time. From inside, every one of these reads as confirmation — the sceptics have been wrong for two years and the participants keep being proved right in real money. None of the signals marks the top, which is why the workable responses are mechanical rather than predictive.
in a bubble most of the eventual loss comes from: The multiple contracting, not the business failing. A share bought at 90 times earnings on the assumption of 45% growth can fall roughly 45% when growth normalises to a still-excellent 22% and the multiple settles nearer 35 times — while the company grows revenue every single year. That is why “but the business is good” is not a defence: the loss came from the price the story was bought at.
why is “it is different this time” so hard to argue against: Because it is usually partly true — bubbles are built on stories that are genuinely accurate. The internet really did change everything, and India’s formalisation is real; what fails is the price paid for the story in advance, not the story itself. Waiting for the narrative to be disproved is waiting for the wrong thing, and reflexively calling every new development a bubble is its own expensive error.
what do people actually do when they think prices have run too far: The responses that hold up are mechanical rather than predictive: rebalancing back to a target allocation on a fixed date instead of on a view, and not adding leverage. Rebalancing reduces equity exposure automatically as prices rise without requiring anyone to call a top, and bubbles rarely ruin people who are unleveraged. Writing down in advance what would change your mind matters too, because later you will have reasons for everything and they will all point where the market has been moving.
can you short a bubble: You can, and it is the response with by far the worst risk profile, because being right about a bubble and early is indistinguishable from being wrong. The position is usually closed at a loss long before the thesis pays, and losses on a short are not capped the way losses on a holding are — the price of what you sold can keep rising. Reducing exposure costs you some upside if the run continues; the asymmetry is the whole reason the two are not comparable choices.