NEW YORK (AP) — Shares of Twitter are surging on a report that co-founder Jack Dorsey will step down as the company’s chief executive.

Twitter’s stock, which has consistently underperformed the market, jumped more than 10% at the opening bell Monday.

CNBC first reported that Dorsey may step down soon, citing anonymous sources.

Twitter Inc. did not immediately respond to a request for comment from The Associated Press early Monday.

Dorsey is also the top executive at Square, a financial payments company that he founded, and some big investors have openly questioned whether he can be effective leading both.