The "soul" in this verse was translated as "life" in the previous verse. In doing this, the connection between the two verses is lost. See this article for more.
This verse consistently uses economic terminology to makes its point but that is lost in translation. However. oddly, the verb translated in the KJV as "profited" is less economic than other terms. The term translated as "gain," however, does refer to a financial profit and is used only in this verse and the similar ones in Mark and Luke. The term translated as "lose/forfeit" refers to a financial loss and is used only in this verse and the similar ones in Mark and Luke. It is not the "lose" in the previous verse. More about the meaning of these words in this article.
Christ's Words in Matthew as a Guide to 40 Days of Prayer.