Yes. We ran into this early on. Setting your bid price(maximum price you are willing to pay for the resource you are spinning up) higher than the average spot price do not protect you against instance termination. Also even if you place your spot bid price at current on-demand price (you only get charged at the current spot market price) your instane will be terminated if there is no resource availble in the spot instance pool. For example, you have spin up an ec2 instance with 100 GB RAM with type spot instance, with bid price set to the on-demand price. If someone else spin up a 100GB as on-demand instance type- if there is no resource left in spot pool, your instance will be terminated.