"Formal methods" includes various techniques such as formal proofs, or using programming languages where the compiler itself formally guarantees security properties.

Techniques that are not formal methods include:

• Hope and pray

• Ask an AI if the smart contract is safe

• Ask an auditor to stare at the smart contract really hard

• Ask the original developer(s) to stare at the smart contract really hard (probably equivalent to "hope and pray")

This market resolves as YES if this has been true at any point in time, even if experts later change their mind (e.g. if AIs become better than formal methods at auditing).

If experts say "yes, ideally, but ain't no-one gonna pay for that, pshaw" or "in theory but not in practice" this does not count.