At what level should you evaluate performance for your Search Ads 360 bid strategies?

Evaluating performance at the Portfolio level is the correct approach because Search Ads 360 bid strategies use machine learning to optimize toward a collective goal across all the campaigns and ad groups assigned to that specific strategy. Since the algorithm shifts budget and adjustments to where they are most likely to drive conversions based on a shared target, looking at individual campaigns or keywords in isolation can be misleading and may show inconsistent results. Assessing the portfolio as a whole provides a statistically significant view of how the strategy is managing the trade-offs between different entities to meet your overall business objective, such as a target CPA or ROAS.