The adoption of a shareholder rights plan by Cumulus Media Inc. is a defensive measure against potential hostile takeovers, particularly in light of Renew Group's significant stock accumulation and expressed intent to acquire more shares. This move is likely to be viewed positively by investors who see it as a step to safeguard their interests and the company's value, potentially leading to a short-term positive impact on CMLS's stock price. The plan aims to ensure that any takeover bid is conducted fairly and at a premium, which could deter undervalued acquisition attempts and signal to the market that the company is taking proactive steps to protect shareholder value.