The end result in either case is usually that the profitable trades cover the losses made by the unprofitable ones in any given period of three months or more, other things being equal. The fact that CFDs don’t usually expire means that traders can hold on to lacklustre trades if the circumstances permit. Such trades might later become profitable. However, as noted in the article on managing risk, traders should avoid stubbornly holding bad trades.
Critical to successful diversification is finding a broker which offers a broad range of symbols, especially forex pairs. Exness offers more than 160 symbols for trading, of which around 100 are forex pairs. You can easily experiment with correlations and knock-on effects in markets by practising on a demo account.