In 2021, one particular small-cap stock rose 400% in 11 months. It had no meaningful change in business fundamentals. The company's revenues were declining. But social media groups were buzzing, YouTube channels were breathless with excitement, and the stock appeared on every retail momentum screen. Millions of new investors bought it. When the bubble burst, many lost 70-80% of what they'd put in. This is herd behaviour at its most vivid.
Why herding is individually rational but collectively catastrophic
Herd behaviour | following the crowd's investment decisions rather than forming independent judgments | seems irrational. But it's individually rational for several reasons:
- Information cascade: Other people's actions contain information. If thousands of investors are buying a stock, perhaps they collectively know something you don't. Acting on others' actions rather than your own limited analysis is an efficient way to process information | when the crowd is genuinely informed.
- Career risk (for fund managers): A professional fund manager who underperforms the benchmark while holding different stocks faces career consequences. Holding the same stocks as everyone else ("closet indexing") means your underperformance is at least in line with peers. Rational self-preservation, collectively harmful.
- Social proof: When everyone around you is making money in a particular theme (2021 small-caps, 2017 mid-caps), the social pressure to participate is intense. Not participating feels like missing out and being wrong.
The problem: when the crowd's actions are driven by each other's actions rather than fundamental analysis, the information cascade carries no real information. Everyone is following everyone else. The resulting price movements are entirely disconnected from underlying value.
How bubbles form and burst | the Indian pattern
India has produced several identifiable bubbles in the last 15 years. The pattern is consistent:
- Phase 1 | Smart money: A genuinely attractive theme (infrastructure, mid-caps, new listings) attracts informed investors. Prices rise on legitimate fundamental improvement.
- Phase 2 | Fast money: Rising prices attract momentum traders. Returns are now driven by price appreciation rather than fundamentals. Valuations stretch.
- Phase 3 | Retail frenzy: Strong returns attract retail investors who see others making money. SIP inflows surge. New demat accounts open. Social media amplifies. Valuations become extreme.
- Phase 4 | Euphoria and denial: Any concern is dismissed ("this time is different," "India's growth story," "retail participation has changed the game permanently"). Volume is maximum. Everyone is bullish.
- Phase 5 | Collapse: Smart money exits. Fast money follows. Retail is left holding the peak. The same stocks that rose 300-400% fall 60-80% over 18-24 months.
The contrarian insight: The presence of extreme herding is a reliable signal | in both directions. Maximum retail enthusiasm near a peak signals overvaluation. Maximum retail pessimism near a trough signals undervaluation. The contrarian investor tracks sentiment indicators (SIP flows, demat account openings, social media sentiment) as contrary indicators to fundamental analysis.
| Bubble / Theme | Peak year | Peak-to-trough fall | Recovery time |
|---|---|---|---|
| IT / Dotcom stocks | 2000 | −70% to −90% | 5 to 7 years |
| Real estate (DLF, Unitech) | 2007 to 08 | −85% to −95% | Never (many) |
| Infrastructure stocks | 2007 to 08 | −75% to −90% | 8 to 12 years |
| Mid/small-cap rally | 2018 | −40% to −65% | 2 to 3 years |
| SME / micro-cap IPOs | 2024 | −50% to −80% | Ongoing |
In every case, retail participation peaked just before the collapse. Maximum SIP inflows, demat account openings, and social media discussion coincided with the price top, not the bottom.
FOMO | the herd behaviour amplifier
FOMO (Fear Of Missing Out) is the specific emotional mechanism that drives retail investors into bubbles at their peak. When a stock or sector has already risen 200-300% and social media is full of success stories, the psychological pressure to participate becomes overwhelming | even for investors who intellectually know the price is stretched.
FOMO is especially dangerous because it creates an asymmetric risk scenario: potential gains are limited (the stock has already risen enormously) while potential losses are large (the bubble can collapse). Yet the emotional pull feels exactly opposite | gains feel likely and certain, losses feel unlikely.
RupeeCase strategies buy and sell based on quantitative factor signals, not social sentiment or recent price performance alone. A stock that has risen 400% in a year may actually be flagged for exit (if momentum has peaked and quality scores are declining) rather than entry. The systematic approach is inherently contrarian to herd extremes | adding exposure when factors are improving and reducing when they're deteriorating. Start at invest.rupeecase.com.
Glossary
- Herd behaviour
- Following the crowd's investment decisions rather than independent judgment. Individually rational (others' actions carry information) but collectively catastrophic when everyone follows everyone else.
- Information cascade
- When people act on others' actions rather than their own private information, passing the same (possibly incorrect) signal down the chain. Creates self-reinforcing price movements disconnected from fundamentals.
- FOMO
- Fear Of Missing Out | the emotional pressure to participate in a rising market/stock because others are visibly profiting. Typically most intense at or near market peaks | precisely the worst time to enter.
- Closet indexing
- Fund managers holding portfolios nearly identical to the benchmark index to avoid career risk from underperformance, while charging active management fees. A form of professional herd behaviour.
Sources & further reading
Quick check, Module 8.4
Bubble Risk Indicator
Bubble warning composite. Three inputs that historically correlate with late-stage frothy markets in India.