It looks like Guarda wallet is mainly closed-source. Only certain components are open-source, not its core wallet. In which case, you might want to consider other alternatives.
What cryptocurrencies do you have, by the way? The most reputable hot wallets I know are normally Bitcoin-focused. Are you open for maintaining at least 2 wallets? Electrum and Mycelium, for example, for your Bitcoin and certain altcoins, respectively?
By the way, what will happen to trading efficiently? Would you be taking out your coins every filled order? That would be costly.
I'm actually invested way more in ETH than I am in BTC.
In that case, you might want to consider either MyEtherWallet or MetaMask. Both are non-custodial and open-source. MetaMask is a browser extension kind of wallet while MyEtherWallet is web-based that has offline options. I think the latter is somehow more flexible than the former. However, it all depends on what else you're heavily into other than hodling ETH. But for plainly hodling ETH, at least temporarily, you can choose either.
Please do your own research. I'm not vouching for these wallets.