GNC Holdings' (>> GNC Corporation) shares tumbled as much as 27.1 percent to hit their lowest in four years, but closed 6.4 percent lower at $29.07. Daily volume was the largest ever according to Reuters data.
The DOJ called a press conference at noon Eastern (1500 GMT) about criminal and civil actions aimed at stemming the sale of unproven nutritional supplements.
No specific companies were named in the announcement, but traders then sold off shares of GNC, Vitamin Shoppe (>> Vitamin Shoppe Inc), Natural Health Trends Corp (>> Natural Health Trends Corp.) and Herbalife (>> Herbalife Ltd.), betting on their declines. Options volume activity also surged.
None of those companies were named by the DOJ. Executives at USPlabs LLC and S.K. Laboratories, which do not trade publicly, face criminal charges related to the sale of unlawful dietary supplements.
Vitamin Shoppe tumbled as much as 10.4 percent to hit its lowest in more than five years, closing down 4.9 percent at $28.19. Volume was the highest for any session going back to Feb. 25, 2014.
Natural Health Trends, which closed Monday at its highest since early June 2000, fell as much as 23.9 percent. It ended down 15.4 percent at $45.47 on its highest volume in more than three months.
At its session low, Herbalife was down as much as 6.3 percent with volume at its highest since early August. It closed 1.5 percent lower at $54.43.
The announcement of the DOJ news conference also triggered a spike in options hedging activity with volume in options of those four stocks at several times the average for a day. GNC options volume was at 35,000 contracts, or eight times what is normal while Herbalife options volume hit 31,000 contracts, or 2.6 times what is normal, according to options analytics firm Trade Alert data. But not all of the trading in these shares was bearish. GNC drew a noticeably large bullish bet where a trader bought 2,700 call options, betting that the shares would close higher than $30 by Friday, or 3.2 percent above their Tuesday close.
(Reporting by Rodrigo Campos and Saqib Iqbal Ahmed, editing by G Crosse)