BlackRock Inc. on Friday temporarily stopped issuing new shares in its $7.7 billion iShares Gold Trust, as surging interest in the precious metal caught the world’s largest money manager off guard.

Investors had piled into the fund so fast that BlackRock didn’t register in time with the U.S. Securities and Exchange Commission to issue more shares. The suspension means that the share price of the fund may deviate from the price of its underlying assets the physical gold until issuance resumes, probably within two or three business days, according to a person familiar with the matter.