When running tests during deployment, are tests ran in parallel?

Question

Specifically, I deploy to my org using a command like this:

sfdx force:source:deploy -u=<accessToken> --sourcepath ./src/main --testlevel RunLocalTests --json --wait 120

When doing this, do the test run in parallel? Is there a way to specify in the command if we want them or not to be ran like that?

Thanks for your answers!

Answer 1

No, tests run during a deployment are always run serially, never in parallel.
There is no option to change that.