Lognormally distributed share returns: Difference between revisions

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But the theoretically worst outcome for a share investor is to lose the whole of their investment - in other words a negative return of -100%.  
But the theoretically worst outcome for a share investor is to lose the whole of their investment - in other words a negative return of -100%.  


It is not theoretically possible to suffer a return of worse than -100%.
It is not theoretically possible to suffer a return of worse than -100%.
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* [[Normal distribution]]
* [[Normal distribution]]
* [[Volatility]]
* [[Volatility]]
[[Category:The_business_context]]
[[Category:Financial_products_and_markets]]

Revision as of 17:57, 1 July 2022

If share returns are lognormally distributed it means that the logarithm of [1 + the share return] has a normal probability distribution.


Normal distributions have infinitely long ‘tails’ both upside and downside - so implying unlimited downside potential when used for modelling share returns.

But the theoretically worst outcome for a share investor is to lose the whole of their investment - in other words a negative return of -100%.


It is not theoretically possible to suffer a return of worse than -100%.

Lognormal distributions - unlike normal distributions - also have a limited downside, so they do not suffer from this theoretical shortcoming.


See also