When shareholders sell into the newly established higher price the stock will drop back down and fill the price gap that was created. Market Makers have been using gaps to line their pockets with money from investors for years. Generally, if you want to purchase the stock that day, place a limit order at the previous day's closing price. You will nearly always get your order filled. When it Gaps Down at the Open.
Traders use the same tricks on bad news.
If they have an excess of market sell orders at the open, they will fill those orders at a ridiculously low price. Always wait for the inevitable bounce before liquidating your position if the news if bad enough and you are looking to preserve your remaining capital. Don't Be Afraid to Add To Positions During Unfavorable Markets. If you have followed the rules and not committed the entire amount you are willing to invest, bear markets can be excellent buying opportunities. Microcap stocks will generally drift down in the absence of buyers, and can drop to ridiculously low levels during bad markets.