At 11:16 am, Matrixx Initiatives became the focus of StockTwits chatter. Trading was halted at 8.56 by 11:34, only to reopen at 6.30 over two hours later. The maker of Zicam nasal spray fell 70% intraday as the FDA revealed a rather unpleasant side effect, permanent olfactory damage. The Zicam products in question account for…