Not really sure, but their developer page claims that the wallet is open-source[1]. If it's accurate, then it's definitely a positive thing.
On the other hand, regardless if it's safe or not, it's really not recommended to hold huge amounts on money through a software wallet. 99% of people should always go with reputable hardware wallets.
[1]
https://trustwallet.com/developer/I like this point. After the falls here and there software part is untrustworthy and anything thats online is sucker punch today or tomorrow. Now the priority is changed. Let us keep the sequence of securities like this: Hardware wallets being the safest one, then paper wallets, software wallets (preferably with Pass phrase + password protection), decentralised exchanges, (not you centralised exchange). That is something everyone should note now and follow whole thinking about storing huge amounts of coins.
