I would say so. Don’t expect any privacy, but there record has been pretty good in terms of security. They use the cold storage and hot storage model.

Cold storage just means that they private keys used to access the Bitcoin is kept offline — that is the private key NEVER touches the internet. Physical security is a relatively easy problem to solve compared to digital security.

Hot storage is where the private keys used to access the Bitcoin is kept online. These Bitcoin are at high risk of being stolen because it is relatively easy for hackers to get access to these — computer security is really hard.

Coinbase probably keeps something like $50,000 - $100,000 in their ‘hot storage’ at any given time. The rest of their Bitcoin is kept in cold storage — which is much safer.