« One million dollars » by Wilfredo Prieto was one of the most talked-about pieces displayed at ARCO Madrid, which took place last week. It consists of a one-dollar bill fit between two mirrors in such a way that the dollar image is indefinitely reproduced. The piece’s selling price is indicated by its name, and Prieto requires that potential buyers sign a contract that forbids them from selling it for any sum other than $1 million. The work is insured for its nominal value and a guard surveys it at all times. With this very original piece, Prieto sought to discuss the relationship between art and the speculative market.