Speculation and market bubbles

Speculation

Speculation means buying an asset (houses, shares, commodities, currencies, cryptocurrencies) not to use it but in the expectation that its price will rise, so it can be sold later for a profit. Speculation can be useful: it adds buyers and sellers to markets and can smooth prices. But it can also be destabilising.

How a bubble forms

A market bubble is a rapid rise in an asset's price far beyond its underlying value, driven by expectations of further rises rather than by fundamentals (rents, company profits).

The chain:

1. Prices begin rising, perhaps for a good reason (low interest rates, a new technology).

2. People expect further rises, so demand increases: demand shifts right, pushing price up further. Expectations become self-fulfilling.

3. Herding and easy credit add more buyers, including those who cannot really afford it.

4. Eventually something changes (interest rates rise, buyers run out, confidence breaks). Expectations reverse; people rush to sell; demand shifts left and supply of assets for sale shifts right.

5. The bubble bursts: prices crash, often below underlying value.

This links to behavioural economics: people do not act fully rationally, following the crowd and over-weighting recent price rises.

Impact on stakeholders

Housing:

• buyers who bought near the peak may end up in negative equity (the house is worth less than the mortgage)
• first-time buyers are priced out while the bubble inflates
• banks face loan defaults and losses, which can spread through the financial system
• construction firms and workers face falling demand and job losses after the crash
• government faces lower tax revenue and possible bank rescues

Stocks and shares:

• investors and pension funds lose wealth when the bubble bursts, so consumption may fall
• firms find it harder to raise finance by issuing new shares
• during the bubble, resources flow to over-valued firms that may later fail: a misallocation of resources
• workers in those firms lose jobs when they collapse

Resources are misallocated both on the way up (too much investment in the bubble asset) and on the way down (wasted projects, unemployment).

Worked example

Explain how expectations of rising house prices can become self-fulfilling.

1. People expect house prices to rise, so they buy now to make a gain or avoid paying more later.
2. Demand for houses shifts right, while supply is inelastic in the short run.
3. So price rises sharply, confirming the expectation and encouraging still more buyers.

Answer: Expected rises increase demand, and with inelastic supply this raises prices, confirming the expectation.

Check yourself

1. Speculation means buying an asset mainly in order to
   • sell it later at a higher price
   • use it in production
   • consume it immediately
   • avoid paying tax
   Show answer

   sell it later at a higher price. The motive is an expected price rise.

2. A market bubble is best described as
   • a fall in price caused by an increase in supply
   • a government maximum price
   • a price rise far beyond an asset's underlying value, driven by expectations of further rises
   • a market with no buyers
   Show answer

   a price rise far beyond an asset's underlying value, driven by expectations of further rises. Prices detach from fundamentals such as rents or profits.

3. A household whose house is now worth less than its outstanding mortgage is in
   • negative equity
   • excess demand
   • a public goods trap
   • unitary elasticity
   Show answer

   negative equity. Negative equity follows a house price crash.

4. Which event is most likely to burst a housing bubble?
   • A fall in interest rates
   • A rise in expectations of future price increases
   • A fall in the number of houses for sale
   • A sharp rise in interest rates on mortgages
   Show answer

   A sharp rise in interest rates on mortgages. Higher mortgage costs reduce demand and break confidence.

5. Herding contributes to bubbles because
   • it increases the supply of assets
   • people buy because others are buying, pushing demand up further
   • it reduces asymmetric information
   • it makes demand perfectly inelastic
   Show answer

   people buy because others are buying, pushing demand up further. Copying others adds to demand regardless of fundamentals.

6. Explain one impact of a stock market crash on households.
   Show answer

   Households that own shares, directly or through pension funds, lose wealth when share prices fall. Feeling poorer, they may cut their consumption, and retirement incomes may be lower.. Wealth effect on spending or pensions.

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Sources

• Pearson Edexcel International Advanced Subsidiary/Advanced Level in Economics specification (2018)

Last updated 8 November 2026. Spotted a mistake? Tell us.