A simple backtest will show this strategy will bring you to an account blow up, tried doing it Quantopian, and the equity curve was at -32% after an year. Leave alone the trading costs.
Now the question you ask while building a strategy, what moves the markets (this is difficult)? And secondly who moves the markets (this is tricky).
When you know these 2 things, which changes a lot on a day to day basis, you are said to have a market understanding. Based on this understanding, ask yourself, is the open price and high price in the first 5 minutes moving the markets? Obviously No. Its just a pattern your eyes noticed on few charts and now they have become a part of the recency bias of your mind. Is the MACD and Bollinger band on your chart that is moving the market?
Markets move due to expectations, and you will be analysing this part first. So what is everyone expecting? A trader, an investor, a market maker, whos expectations are over powering other expectations. Auction market theory gives you perspective into this type of reasoning, based on mean reverting days and trending days.
Expectation ---> Orders ----> Volume ----> Price ----> Indicator
This is the occurrence cycle. Anything on the left of the price will lead and on the right will lag. Now you know how to think while developing a strategy.
A good strategy is a function of price, volume and volatility. A robust strategy will be function of all the 4 occurrences. Like
1. news, events, inter market analysis, intra market analysis, sector etc. (which make expectations)
2. Order book/Tape (orders)
3. Time and sales, order flow, volume (volume)
4. Price action (price)
I have worked with prop desks, which make you think on the lines of the first occurrence, which is expectation. It is high risk but high reward since you capture the full move. Then there is another institutional community like scaplers and jobbers which make a living by analysing the second occurrence. It is low risk, fixed reward.
And then there is the retail trading community (majority of them) which struggles with the 3rd and 4th occurrence all their life. High risk, low reward. Further they go on to using indicators derived from price to predict price. How contrary that sounds?
Hope this helps.