Brent prices are up more than $1 after this announcement, which was a Reuters poll showed was expected by 15 of 22 oil analysts. That means it wasn't fully priced in and you can see that from the reaction.

The state news agency carried the headlines and said the cut could be extended further or deepened. Many analysts expect them to taper the cut by half in October.

WTI crude 30m
WTI crude 30m

Full statement:

Saudi announcement