This circumstance may have important and potentially adverse allocative consequences on the economy. In particular, if asset prices do not accurately reflect the productive potential of the underlying asset, investment will be channeled to the wrong sectors.
However, an asset-price boom in a specific sector might simply reflect investor expectations of higher productivity rather than a bubble, a term I will define in a few moments. Investment would still tend to be channeled to that sector, but for good reason in this instance.