divergence
noun [ C or U ]
uk/ˌdaɪˈvɜːdʒəns/ us/dɪˈvɜrdʒəns/a situation in which two things become different, or the difference between them increases:
a divergence of opinion
The figures reveal a marked divergence between public sector pay settlements and those in the private sector.
Funds investing in credit-rated bonds are all holding much the same investments, so the divergence in performance is not significant.
a considerable/significant/sharp divergence