The antonyms for "traded last" could include words like "purchased first," "kept," "held onto," or "retained." These antonyms suggest that an item or asset was not sold, swapped, or exchanged for something else. Instead, it was maintained in its current state or ownership. In the context of financial markets, "traded last" implies that a security or asset was sold at the end of a trading day, whereas antonyms like "held onto" or "retained" suggest a long-term investment strategy. In general usage, antonyms for "traded last" might include phrases like "saved for later," "cherished," or "kept in reserve.