The survivors undergo successive rounds of mutation resulting in better and better antibodies during the course of an immune response. (sciencedaily.com)
However, there are also obstacles that get progressively worse which will slow down you and your opponent in successive rounds. (playstationlifestyle.net)
The only worry investors should have is if index selling leads to successive rounds of ETF and passive mutual fund selling, which could lead to more negative feedback loop selling. (dailytradealert.com)