Where Souls Are Bought And Sold? Poem by Emmanuel George Cefai

This is a puzzling poem, because it raises an unresolved issue. The marketplace certainly is a slave market, selling souls instead of bodies. My first question is what would a soul-slave be? What productive labor for the slave owner would soul-slave provide? What does the speaker of the poem mean by INVESTING in souls? Collecting them? Does he mean to free them? ... SLAVERY is a vexed issue for an American like myself - and it should be - because our prosperity in the early years was based cruelly on African slaves, and it took a devastating Civil War to change that practice. In your poem slavery is some kind of metaphor but it is unclear to me what it means. Into that vacuum then these historical images rush. If the poem were longer, I'd have a context but....