BUYING AND SELLING RESERVED INSTANCES

Unfortunately, standard reserved instances, by their nature represent a commitment to a particular instance type, tenancy etc. You receive a discount from AWS, in exchange for committing to use a particular instance type/family in a specific region.

The only way available to trade them is if you sell them on the AWS Marketplace.

If they are convertible reserved instances, then you can exchange them for another convertible reserved instance with a different configuration, including instance family, operating system, and tenancy.

While this is not helpful to you today, as you currently have reserved instance, consider using Compute Savings Plans in the future - for a little less discount these apply to all compute, including Fargate and Lambda.

Hi there.

The best way to find out is to open a billing case with AWS Support so they can advise whether your only option is the AWS Marketplace or anything else.

I hope this helps.