There is no thing as the best indicator for BUY decision because traders have different strategies. Aside from RSI and MACD which you have disregarded already, I am using Bollinger Bands and Stochastic RSI in trading. These 2 are the ones I used always although there are times that it is not working, its only an indicator and if it always works there are no traders who are losing right now. You need to pick an indicator that suits you in trading.
although there are times that it is not working - agreed !
Just buy the deep. be on market every day and you will know when the deep is. You will feel it. I know it sound stupid and it looks like a 6 yo kid wrote it but there is no working indicator. RSI will be below 30 for weeks in bear market and for 1 s with huge pump after it in bull market. Price act different during bear and bull market. When market is stabitalizing after bull will act different and when it will stabilize after bear too. I was trading stock for years beafore i jump to crypto. Ive tried sooo many indicators. Even if some of them worked great then market change direction/speed and it become rabish.
Nothing will replace expirienced trader. How to become one? Make as manny trades as you can with as low bet as you can. Do a lot of mistakes and learn from each. After some times you will earn money but then market will change its speed and you will need to learn new things.
Many of this indicators was made years ago. When there were sell trading bots, no IA bots and they were invented to trade on stocks with low variability (and no arbitrage from dozens of exchanges). Many of them was made in times when you want to make transaction you need to call your brokeror even go to exchange and in personally make transaction. They just dont work here. And even if than they wont when market will change a bit.
When i came to the market and my first impression is "wtf is this soo cheep". then i look at the chart and see so much panic and irracional sell than I just simply know that it will be pumped in next few days becouse if I was a whale ill pump it - i wont miss that oportunity.
Whales dont look at indicators.
We all know that 90% investor are loosing on stock market. So this 10% gets all money lost from 90% invetors. They get 10 times more than each one from this 90% lose. To earn that much you need to put huge money into market. This is simple math that shows that only whales are winning on market. To earn you need to swin close them. And they are not looking on bolinger. They are showing you buy opportunity when they wont to sell to have higher demand. Crypto maket is quite different because we are in bull market since 2008 (with small correction - even 19000-6000 is small correction according to fact that it was worth <1$ few years ago). Its easier to earn but whale earns much more.