Chart by TradingView Image Sensing Systems builds and sells video and radar processing products for the intelligent transportation systems industry, with clients worldwide. The company was founded in 1984 and is based in Saint Paul, Minnesota. The $4.30 level is what is known as a support level. At support levels, there is more than enough demand to absorb all of the supply of shares. This means that sellers can sell all they need to without a fear of pushing the price any lower. When stocks or markets are in downtrends, they often pause or reverse when they get to support levels. When a stock that is in a downtrend reaches a support level and reverses its trend and moves higher, it is because buyers in the market get the sense that there are large buyers around … i.e. the ones that formed the support. Some investors start to buy the stock because they are afraid these large buyers will eventually come off of their prices levels and push it higher. These investors want to get in ahead of this. This is what causes the rebound.