As any online device is always prone to hacking, it's recommended to go for a cold storage, especially if you hold big amount of fund.
And if you want to use a hot wallet for any reason, you should avoid any close-source wallet like trustwallet. There is no way to know how the keys are generated on trustwallet and whether they are stored in their server or not.


Considering that trustwallet is close-source, it's may not be as safe as your device. It's possible that there's a vulnerability in trustwallet that cause people to lose their fund while their device is safe and not infected with any malware.