Smart Bids is a proprietary Merch Jar algorithm that automates bid optimizations for you to hit your target ACOS. Smart Bids will automatically adjust keyword and target bids to reach your ideal CPC for any campaigns that have smart bids enabled.
Smart Bids currently adjusts bids on any keywords or target that have two or more orders in the past 30 days, not including today's or yesterday's data. Bids are adjusted up to once per day by 1-3%, depending on how far outside of the ideal CPC your average CPC is.
Any changes Smart Bids makes can be found in your Logs page: https://app.merchjar.com/logs
Additional Smart Bid support for keywords and targets with fewer than two orders is on the development roadmap.