I wanted some help in looking for suitable articles/literature. Suppose an investor has a bunch (bouquet?) of quantitative strategies already generating trading signals for him. If he comes up with a new strategy, how can he test if it overleverages the securities in his portfolio by generating essentially the same trading signals or is independent of his existing strategies? A rudimentary method might involve comparing the sign of closing and intraday positions of each pair of strategies (long, neutral, or short), but are there any better ways of achieving the same? Further, if a strategy in the portfolio seems similar to the new one, how do you decide if you should swap them, include both, remove both, or discard the new one altogether?
This isn't literature but Quantopian (a crowd sourced hedge fund) selects new strategies if their returns have a low correlation (+- 30%) with other strategies in their portfolio (as well as other performance criteria!). - https://www.quantopian.com/allocation