leptokurtosis: meaning, definition, pronunciation and examples

C2
UK/ˌlɛptəʊkɜːˈtəʊsɪs/US/ˌlɛptoʊkɜːrˈtoʊsɪs/

Technical, Academic

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Quick answer

What does “leptokurtosis” mean?

A statistical property describing a probability distribution with fatter tails and a higher, sharper peak than a normal distribution.

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Pronunciation

Definition

Meaning and Definition

A statistical property describing a probability distribution with fatter tails and a higher, sharper peak than a normal distribution.

In statistics and finance, leptokurtosis (positive excess kurtosis) indicates a distribution where extreme outcomes (both high and low) are more likely than in a normal distribution, implying greater risk of outlier events.

Dialectal Variation

British vs American Usage

Differences

No significant differences in meaning or usage. Spelling and pronunciation are consistent.

Connotations

Purely technical term with no regional connotative differences.

Frequency

Extremely low frequency in general discourse but equally used in relevant academic/professional fields in both regions.

Grammar

How to Use “leptokurtosis” in a Sentence

The [dataset/model/distribution] exhibits leptokurtosis.Leptokurtosis is present in [noun phrase].to test for leptokurtosis

Vocabulary

Collocations

strong
positive leptokurtosisexcess leptokurtosisfinancial returns show leptokurtosismeasure of leptokurtosis
medium
the leptokurtosis ofcharacterised by leptokurtosisindicates leptokurtosis
weak
significant leptokurtosishigh leptokurtosisextreme leptokurtosis

Examples

Examples of “leptokurtosis” in a Sentence

adjective

British English

  • The leptokurtic nature of the data invalidates the standard model.
  • We observed a leptokurtic distribution in the results.

American English

  • The returns are leptokurtic, suggesting high tail risk.
  • A leptokurtic distribution was fitted to the dataset.

Usage

Meaning in Context

Business

Used in quantitative finance and risk management to describe asset return distributions with higher-than-expected probabilities of extreme gains or losses.

Academic

Core term in statistics, econometrics, and probability theory courses and research.

Everyday

Virtually never used.

Technical

Precise term in data analysis, statistical software output, and scientific papers describing distribution shape.

Vocabulary

Synonyms of “leptokurtosis”

Neutral

positive excess kurtosisheavy-tailedness

Weak

tail risk (context-specific)

Vocabulary

Antonyms of “leptokurtosis”

platykurtosisnegative excess kurtosis

Watch out

Common Mistakes When Using “leptokurtosis”

  • Pronouncing it as 'lepto-kyoor-toe-sis' (correct: 'lepto-ker-toe-sis').
  • Using it to mean simply 'high variance' (it's about the shape, not the spread).
  • Confusing it with skewness (asymmetry).

FAQ

Frequently Asked Questions

No. Kurtosis is a general measure of the 'tailedness' of a distribution. Leptokurtosis is a specific type of kurtosis where the value is greater than that of a normal distribution (excess kurtosis > 0).

It signals that the probability of extreme market events (like crashes or bubbles) is higher than predicted by models assuming a normal distribution. This is critical for accurate risk assessment and pricing.

The daily returns of a stock market index (like the S&P 500) are famously leptokurtic. Most days see small changes, but the frequency of very large gains or losses is greater than a normal distribution would suggest.

The opposite is platykurtosis (excess kurtosis < 0), which describes a distribution with thinner tails and a flatter, broader peak than a normal distribution.

A statistical property describing a probability distribution with fatter tails and a higher, sharper peak than a normal distribution.

Leptokurtosis is usually technical, academic in register.

Leptokurtosis: in British English it is pronounced /ˌlɛptəʊkɜːˈtəʊsɪs/, and in American English it is pronounced /ˌlɛptoʊkɜːrˈtoʊsɪs/. Tap the audio buttons above to hear it.

Learning

Memory Aids

Mnemonic

Think of a LEPTOn (a tiny, fast particle) being KURT (sharp/abrupt) – a 'lepto-kurt' distribution is sharply peaked with 'fast-moving' extremes in the tails.

Conceptual Metaphor

A mountain with a very sharp peak and steep, long foothills (the tails), compared to a gently rounded hill (normal distribution).

Practice

Quiz

Fill in the gap
Asset returns with are riskier for investors because they imply a higher probability of extreme market moves.
Multiple Choice

Which of the following is the BEST definition of leptokurtosis?