Archive · 2 Sep 2026
India’s Market Signals Reveal Bubbles Before Crashes—But Not All
Sometimes stock prices rise much higher than company earnings can reasonably support.
This is called a bubble.
Researchers use mathematical tests to look for unusual price increases, risky trading patterns, and herd behaviour.
Some tests found warning signs before parts of the 2000, 2008, 2007, and 2017 market episodes.
In 2024, Indian mid-sized and small companies’ shares rose much faster than the Sensex.
Those shares later fell sharply in March 2025, and regulators warned that prices had become too frothy.
However, another 2025 market fall was linked to US tariffs and foreign investors taking money out, not necessarily a bubble.
This means warning tools can help, but they cannot predict every crash.
Regulators also have only a short time to act and may hesitate because their decisions can affect markets.
Research suggests Indian markets can show statistical signs of excessive exuberance before some major downturns.
Unit-root tests identified exuberance in several Indian indices during the 1999–2000 dot-com period, but not in the Sensex or Nifty Bank.
Variance-bounds analysis found indirect evidence of herd-driven bubbles around the 2008 crisis, while the PSY method flagged episodes around 2007 and 2017.
Mid- and small-cap indices surged in 2024 before falling sharply in March 2025, prompting regulators to warn of froth and irrational exuberance.
Early-warning tools have limited lead times and cannot reliably identify every selloff, including the 2025 decline attributed to tariffs and foreign outflows.
- Who
- Researchers, Indian market participants, the Securities and Exchange Board of India, the Association of Mutual Funds in India, and the Reserve Bank of India.
- What
- The article examines whether statistical indicators can detect bubbles and financial instability in Indian markets before crashes.
- When
- The evidence covers episodes from 1999–2000 through the 2024–26 mid- and small-cap period, including the March 2025 correction.
- Where
- India’s stock markets, including indices such as the Nifty 50, Nifty 500, BSE SmallCap, BSE MidCap, and the Sensex.
- Why
- The aim is to determine whether market crashes described as surprises leave measurable warning signs beforehand.
Evidence Supports Early Warnings
Signals Have Important Limits
Can bubbles be detected?
Evidence Supports Early Warnings
Unit-root, variance-bounds, and PSY tests identified patterns associated with exuberance or bubbles before several historical episodes.
Signals Have Important Limits
A security’s fundamental value is difficult to determine, and a signal may appear in some indices while being absent from others.
Did regulation respond effectively?
Evidence Supports Early Warnings
The Securities and Exchange Board of India and the Association of Mutual Funds in India warned of froth, required fresh stress tests, and restricted some lump-sum fund inflows within months of the 2025 correction.
Signals Have Important Limits
The article says regulators often act reactively, with the Financial Sector Stress Index providing only a few months of warning and policymakers oscillating between tightening and easing.
Can the tools predict every crash?
Evidence Supports Early Warnings
Statistical dashboards can help identify self-reinforcing price loops and excessive valuations before some downturns.
Signals Have Important Limits
The January–February 2025 selloff was attributed to US tariffs and foreign outflows rather than a valuation bubble, showing that these tools do not capture every market shock.
- Historic market fall
- The Bombay Stock Exchange index fell 15.52% on May 17, 2004, leading to a trading halt.
- Dot-com evidence
- A right-tailed unit-root test found exuberance in the Nifty 50, Nifty Next 50, Nifty 500, and BSE 100 during 1999–2000.
- 2008 evidence
- A variance-bounds test applied to the CNX Nifty found indirect evidence of a herd-driven bubble around the 2008 crisis.
- PSY findings
- The Phillips-Shi-Yu method flagged bubble episodes in the Nifty 500 around 2007 and 2017.
- 2024 gains
- The BSE SmallCap and MidCap indices rose 30.7% and 28.3%, respectively, while the Sensex gained about 10–13%.
- March 2025 correction
- The Nifty Midcap 150 fell 20.5% and the Smallcap 250 fell 25.4%.
- Later valuations
- By July 2026, the Nifty 50 P/E was about 20.9, compared with roughly 33.5 for mid-caps and 32.8 for small-caps.