Any change in the tentative price range of an offering. This occurs in 2 distinctly different market conditions. If IPO is in high demand, the underwriters will often times try to balance the equation for the issuer by raising the tentative offering price. If this does not diminish demand, there could be yet another upside revision. Conversely, if the demand for the deal is low, the price could be revised lower to try and stimulate interest. This is generally unsuccessful as the deal is then view upon as damaged goods even though it may offer greater value to the investors.