When you see a huge percentage move in a stock, look at the daily volume. Multiply that volume by the stock price and see just how many dollars were spent to move that stock. In small companies with thin trading, a few thousand dollars -- or less-- of trading can move the market cap of the company by millions.
A trader hits a 1.00 bid and sells one hundred shares of a stock that last traded at 1.20. The stock has 20 million shares outstanding. Pre-trade the market cap was 24 million dollars. Post-trade it was 20 million dollars.
What's going on is that someone with a laptop and an Etrade account put in a market sell order for a hundred dollars worth of stock and the computer hit the highest bid out there. Total transaction $100. Not exactly a mad rush for the exits.
More like one of the five couples in the movie theater leaving early to send the babysitter home.