Hidden buying by it self is NOT telling us that the price is going to change trend, but it is telling us that demand has appeared at those prices. Remember that the price has inertia and momentum, you will have higher probability trades trading with the trend. For example, before bar 26 the price has been moving higher, it is a major sign of strength and having that sign in the background, as soon as the price resumes the uptrend you could look for longs on smaller time frames.
It is very important to read the market and understand what every bar is telling us. After bar 28 you can expect higher prices and use trend channels and support and resistance to have a projected take profit, but you have to read the market bar by bar because supply could hit the market again and you need to be ready to react to that moving SL to break even, locking some profit or just closing the trade. Your strategy and your trading plan have to define how you manage your positions.
Remember that you read the market and you do what it tells you to, you do not wait for the market to do what you want it to do.