This document compares advertising exchanges to Wall Street exchanges and stock markets. It notes that while Wall Street has strict listing requirements and regulations for traded assets, advertising exchanges have no listing requirements or monitoring of traded impressions. Unlike stocks, impressions are not fixed assets and expire quickly. It also notes that while rating agencies evaluate financial instruments, there is a lack of transparency around methodologies for evaluating digital advertising. The conclusion is that just as one should diversify financial investments, advertisers should benchmark exchanges to ensure performance and not rely on any single platform or product.