The phrase "corner the market" means to take complete control over a particular product or service in a particular market. The antonyms for this phrase would be to release or distribute the market. Distribute would mean to spread the resources equally across the market, therefore, not controlling the entire market. Another opposing word would be to share the market, which means to split it amongst competitors, allowing for fair competition within the market. Lastly, the word relinquish would be another antonym as it means to give up or surrender control, allowing for other competitors to enter the market. In summary, antonyms for corner the market are to distribute, share and relinquish the market.