If you trust ETH you can invest in Bitcoin Cash. Seems strange? There was news from Buterin. He believes that Ethereum needs to be scaled, for this, it is necessary to integrate third-party blockchains, and that the BCH blockchain matches these goals. He said that in Ethereum there are already all the necessary mechanisms to confirm blocks of Bitcoin Cash.
But is it a good way of investing? You have ETH which already is a risky altcoin and instead of buying Bitcoin or more ETH you decide to buy another altcoin that depends on BTC and ETH. If Vitalik changes his mind and doesn't use BCH blockchain BCH will remain as useless as it is now.
I wouldn't invest in a coin that doesn't do anything and needs support from people like Buterin to mean anything.