If you are having issues with your batch updates, here are some hints that may resolve the problems.
Batch updating sell price based on MSRP instead of market price (this will set all of your prices to 0.00)
Most products, unless you have set them, do not have MSRP data.
Not only will all of your prices in the batch update become 0.00, but it will also create problems with your market place integrations (eBay, Amazon, and TCGPlayer).
Batch updating by "Set Qty to" instead of incrementing or decrementing qty
This will change all of your quantities to whatever number you have set.
Accidentally batch updating "Set Qty to" instead of "Opt Qty"
This will overwrite the quantities of any product pertaining to that batch update by whatever number you were trying to set your "Opt Qty" to. This could potentially cause oversells if you do not fix this right away (since most "Opt Qty" are normally set at a higher number, such as 20).
Note: It is important to always double check the parameters you have set before running any batch update because batch updates are irreversible and cause many issues if not submitted properly.
See our How to Batch Update knowledge base article for instructions on how to batch update products.