Skip to content

FRM Part II · FRM Exam Part II · Portfolio Construction

A manager's information ratio is 0.80 with a skill level (IC) of 0.04 under the basic fundamental law. The manager wants to raise the IR to 1.20 without changing skill per bet. Assuming bets stay independent, by what factor must the number of independent bets increase?

Breadth must rise by a factor of 2.25. Since the information ratio is proportional to the square root of the number of independent bets, a 1.5-times increase in IR (from 0.80 to 1.20) needs 1.5 squared, or 2.25 times as many bets, if skill is unchanged.

  1. A2.25Correct
  2. B1.50
  3. C3.00
  4. D1.20

Explanation

IR is proportional to sqrt(breadth), so breadth must scale with the square of the IR ratio: (1.20/0.80)^2 = 1.5^2 = 2.25. Choosing 1.50 forgets that IR grows with the square root of breadth. Original breadth is (0.80/0.04)^2 = 400, and the new breadth is (30)^2 = 900, which is 2.25 times.

Did you get it right without looking?

One question tells you little. A timed set on Portfolio Construction shows your real accuracy, how long you take and where you lose marks.

More Portfolio Construction questions