Answer:
-1.0
Explanation:
Diversification in a portfolio refers to spreading investments in such a way so as to minimize risk.
The correlation coefficient r between two securities signifies how return from one security is related with another security. For example, two securities of the same sector may move in the same direction or positively correlated as in if price of one rises, the price of other rises too maybe not by the same margin.
In case of a negative correlation, the security returns move in opposite directions i.e the securities are least related to one another.
Maximum diversification is achieved when r is equal to -1 i.e the two stocks move in opposite direction by the same magnitude.