As a Man of the Sea
I find these 20% rules hard to accept
All Ships are different in Size Weight and Design
and will handle the Same Seas and Weather conditions VERY DIFFERENTLY
EG
Heavyweights : Both Large and Medium etc etc
Middle Weights: Both Large and Medium etc etc
Small Weighted: Both-Small and Smaller etc etc
Crikey When the DOW hit -20$ off the top
most shares had already fallen ~ 30% and - 50%
and the MOST money had already been lost
Some sort of volatility multiplier should be formulated IMHO
Otherwise
Each and Every ship Handles the Seas and Weather conditions in a unique way
There is no easy way to judge how sea-worthy a craft is without surveying how she Handles the Waters
I wish you well on your journey of discovery and will follow closely
PS: Do you know why The Bear is the Symbol of a BEAR market
and The Bull is the Symbol of a BULL market?
Well
The Bear's paws strikes Downwards when it fights
and The Bull's horns thrust upwards