Well, according to my research, smart contracts are exploitable, (based on no code is perfect) the worst thing about it is that they are irreversible on Eth blockchain, except the coder launches a new one or abandons it,its mostly the second option. But Eth foundation came up with a committee of bounty hunters who scrutinize the codes of the contracts before execution. So steps have been put in place to mitigate exploits, buut its not just 100% foolproof.
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