Not sure about immediately. If you look at the price action during insider purchases, the price can actually tail off a bit as the large purchases offer liquidity and draw the trading volume to a level to clear. That is why you sometimes see a stock tick down over a few days into big bids sitting below the last shown bid. The key is that they are buying, and then the key is when they are finished buying. The stock will go higher afterwards, but sometimes it takes a bit of time because the continued liquidity draws sellers down from higher levels.
But agreed that any insider buying at this level sets up the trade to higher levels, 8+.