A chip represents a financial claim. I have a right to transfer my claim to another. That i all selling a chip does. Some state regs may allow a party to whom a claim is against to void the obligation under certain circumstances, but the item that represents the claim still has a prospective value.

Old Stocks may be bought and sold, but if a stock is replaced, the old version is not recognized by the company, but they can't reclaim it without compensation.