The antonyms for the term "cashed chips" could be many, depending on the context. If we talk in terms of a casino, the opposite may be 'uncashed chips', as they represent the ones that are yet to be exchanged for real money. They may also be called 'unredeemed chips,' 'unclaimed chips,' or 'un-encashed chips.' On the other hand, if we take it as a metaphorical sense, opposite terms might vary. It could be 'missed opportunity,' 'lost then', or 'let go chance.' The antonym may differ in meaning depending on how we frame it. However, the crucial thing is to understand what the term itself means before trying to find its antonym.