A computer implemented method for maintaining a leveraged or reverse exchange traded product is provided which includes electronically monitoring, with a computer, a change in value of a product sold on an exchange, ECN, or ATS; and calculating, with a computer, a leverage ratio, wherein the leverage ratio is dg(r)/dr=c(1+r)c−1, and wherein r is a current cumulative return of the product during a current trading day, and c is a constant, and wherein the leverage ratio is equal to the number of underlying shares required to provide the target return with respect to one share of the product.