Oct 22 (Reuters) - The S&P 500 and the Nasdaq opened lower on Friday after chipmaker Intel warned of lower profit margins, while Snap Inc led declines among social media firms after flagging a hit to digital advertising from privacy changes by Apple. The Dow Jones Industrial Average rose 4.64 points, or 0.01%, at the open to 35,607.72. The S&P 500 opened lower by 3.66 points, or 0.08%, at 4,546.12, while the Nasdaq Composite dropped 57.64 points, or 0.38%, to 15,158.07 at the opening bell. (Reporting by Devik Jain in Bengaluru; Editing by Arun Koyyur)