Yes. Though there is one caveat and one exception, I believe.
The caveat is that the race that built the trade good must maintain ownership of the planet on which it was built. Further, a race that conquers or otherwise gains ownership of that planet also gains the trade good. I must confess, though, that I have never checked to see if a trade good that I acquired by conquest appears in my list of trade goods that I can sell. I think it does, but I cannot confirm it right this instant.
As for the exception, it is the speed increase trade good (galactic accelerator?). That is, the builder gets it and can sell/trade it, but I think it is a known bug that the one getting it by purchase or trade was determined NOT to gain the speed increase. In short, it turns out to be a con! (though apparently an unintended one)
