At 0706 GMT, Aramco shares were down 0.14% at 34.50 riyals.
They have lost almost 11% since hitting a high of 38.70 riyals.
The IPO was priced at 32 riyals per share, valuing Aramco at $1.7 trillion, making it the world's most valuable company.
(Reporting by Saeed Azhar; editing by Jason Neely)