It is so damp in northern California they say that everything will either rust, root, or rot. But we have the assurance of Jesus that treasures laid up in Heaven will neither rust, nor rot.
In His day wealth was often in metal or cloth which did in fact rust and rot. our treasures may be intangible, but that does not mean they will last. Recession or inflation will reduce them in time. But treasures laid up in Heaven are not affected by either. We may have to change the image from that of Jesus' day to our own, but the truth behind the image is unchanged. The only wealth we ever really keep is the wealth we give away.