Northern Star Resources is trading 7.91% higher at A$23.86. The significant share price surge follows the company's rejection of an unsolicited takeover proposal from Gold Fields. - Northern Star confirmed it rejected the offer, calling it highly opportunistic and stating it materially undervalued the company's assets. - The proposal implied an equity value of A$38.7 billion using September 11 prices, with Gold Fields reportedly considering next steps. - News reports explicitly link the rejected bid to the company's share price movement today.