Giant Japanese Conglomerate Flash-Crashes 20% At Open

Tosoh Corporation, the giant Japanese petrochemical conglomerate, collapsed over 20% to below JPY800 shortly after the Japanese open, on volume eleven times average as traders scrambled to find out the catalyst. There was no news of course - just another flash-crash in a world of limited liquidity at the margin (where a small options-arb fund can drive the US equity market for a week).
Share trading was halted for 25 minutes and re-opened unchanged...
Bloomberg notes Tosoh was not available for comment but: