That's a good question!
Adobe Media Optimizer evaluates bids for all the keywords in an optimized Portfolio. If there is no change in the bid (i.e. it is the same bid that was set yesterday), then we do not need to change the bid for the keyword. The bid from yesterday can continue on the Search Engine.
If you see bids executed for 358932 keywords, that means those keywords had a different bid than the bid that was set the day before. The bids are being evaluated for all keywords though.