Matrix Service Co. fell 21.5 percent to $22.86. Kamada Ltd. fell 18.7 percent to $5.82. Mitcham Industries Inc. fell 13.0 percent to $11.30.
Take a look at some of Wednesday's midday movers:
Michael Corbett, portfolio manager at Perritt Micro Cap Opportunities Fund, says high oil prices offer investors opportunity -- via micro cap energy companies.