广告科技公司MNTN Inc.（MNTN）美国IPO首日开盘上涨31.25%，报21美元，此前给出的IPO发行价为每股16美元。

Core Viewpoint - MNTN Inc., an advertising technology company, experienced a significant increase in its stock price on the first day of its IPO, opening at $21, which is a 31.25% rise from the IPO price of $16 per share [1] Company Summary - MNTN Inc. is an advertising technology company that has recently gone public [1] - The IPO price was set at $16 per share, and the stock opened at $21 on its first trading day [1] - The opening price reflects a strong market interest and positive investor sentiment towards the company [1]