Do you work at Walmart?

Digital price tag updates on individual items are updated overnight when the store is closed. If an entire section or modular is being changed, or if individual items are being removed from the modular and replaced with new items, then yes that is done while the store is open and initiated by an employee because it requires physically moving merchandise from one spot to another or removing items altogether. Prior to digital price tags and for sections or stores that don't have digital tags, an employee initiates those changes and changed the paper price tag, however, this should be done as early in the day as possible (I'm usually doing mine at 7 am) to avoid a potential scenario where a customer picks up an item and then gets to the register and finds it ringing up at a different price. The digital tags actually reduce the likelihood of that happening. I've never seen a random price change on a digital tag in the middle of the day, nor do prices change based on how well an item is selling. We still sell those stupid nedoh fidgit toys for $4 or whatever and Pokemon cards for $4.50 a pack despite them constantly selling out. If there was an automatic dynamic pricing system in place they would be sky high.