Shares of New York Times Co. /zigman2/quotes/202090840/composite NYT -0.18% were popping more than 10% in afternoon trading Thursday after ValueAct disclosed a stake in the media company. ValueAct Capital Master Fund and related entities own 11.0 million shares of the New York Times, amounting to a 6.7% stake, according to a filing with the Securities and Exchange Commission. ValueAct said in the filing that it used ValueAct Master Fund's working capital to fund the purchase, the aggregate price of which was about $350 million. Parties at ValueAct "acquired the securities of the Issuer reported herein based on their belief that the securities were undervalued and represented an attractive investment opportunity," per the filing, which also noted that representatives of ValueAct "have had and anticipate having further discussions" with New York Times officers. Shares of New York Times have gained 8.0% over the past three months as the S&P 500 /zigman2/quotes/210599714/realtime SPX -1.25% has added 7.6%.