A half - life of 1.0
typically means roughly 100 % annual
portfolio turnover; a half - life of 10.0 means only about one - tenth of the
portfolio turns over in any given year.8 Strategies and
factors with longer half - lives, such as small cap and profitability, are likely to have
portfolios that change slowly from one year to the next, making it much easier to tease out the structural alpha.