理解Barra Risk Model：Investment Tools History

• Investment Tools History

  Time	States	Investment Tools
  1950之前	1. There was no concept of systematic, or market-related, return. 2. Return was a rise in the value of an asset and risk was a drop in the value of an asset.	intuition; insightful financial analysis
  1950	Risk (as standard deviation) can be divided residual risk and systematic risk; non-market-related risk(residual risk) can be minimized, market or systematic risk cannot be eliminated by diversificaiton.