Not systematic; not founded upon or in accord with a system; not having a defined system or plan; lacking regular order, distribution, or arrangement.

Synonyms See irregular.

adjective. Not systematic

adjective. lacking systematic arrangement or method or organization

"Sharpe's proof depends upon the assumption that all investors effectively free themselves of "unsystematic" risk by diversification and receive a risk premium only for the remaining "systematic risk" (he argued that rational investors in a perfect market would arbitrage away any premium gained in return for avoidable risks)."

orderly  systematic  

Vedic  cursory  deistic  desultory  excursive  

aimless  amorphous  broken  capricious  careening