Japan's biotech stocks have benefited from a spike in interest from retail investors driven in part by last October's Nobel Prize for a Kyoto University stem cell researcher. Company executives who spoke with BioCentury are wary that there could be an equally precipitous outflow - indeed, there are signs the rally is ebbing - and are mulling raising funds while the prices are still good.

Since the beginning of the year, Japanese biotechs have seen their shares rise 71% based on an equal price-weighted basis (see "Japanese Biotech Performance," A11).