If that were the case, then there would be absolutely no benefit from having a stop vs terminate. Unless you've written data to the EBS volume, but in these cases where the boot time is critical most of them are some sort of read-only volume anyways. The fact that an EC2 can be stopped or terminated should immediately suggest speed might be a difference in reaching the running state. In the EBS docs, it clearly states that if you keep an EBS volume around either attached to a stopped EC2 or detached and left in your pool of volumes, you will be charged for that volume.