,
Because at the time you do not know if it is a true trend change or just a correction that will recover. It is not straight down, not always clear in the moment and it usually takes a around a year to work its way down to the bottom with many rallies in between. It is not as simple as you are making it out to be. No offense, but I can tell by the way you are talking you do not have the experience and are new to crypto. The market at some point will humble you. Talk to anyone in the space for 4+ years, I promise you they will reiterate my sentiments if they have made real money and kept it. I have already made the life changing money you spoke about wanting in this market, just offering some advice to avoid some pitfalls I have made in the past. I would be even farther along than I am now if I could avoided some mistakes. Genuinely wish you luck though just try and keep a open mind.
I mean I get that it isn't always clear immediately but it is pretty clear fairly quickly if you are looking at the MACD/Signal line crossover points and the EMA12/ EMA26 crossover points along with the RSI. And if you don't know what those are then you were kinda flying blind.
I prefer looking at the 1 hour one for day to day and the 1 day one for longer trends...obviously shorter periods like 30 minutes, 15 minutes and even 5 and 1 can help you catch quick peaks and dips but it appears overall the 1 hour one holds the most weight on a day to day basis...
I will not put money into something until the 1 minute crossover point is reached where it trends positive...or at the very least where it starts strong upward momentum towards the crossover point from a very low position and the 5 minute crossover point is trending upward. This signifies it will be increasing and the 1 minute crossover is the most accurate way to find the bottom of the upswing point. However, depending on the other points it might be short lived, so that is not good enough to check on it's own.
This minimizes the risk even when things are "looking good" those tell the real story about what is happening and if it is likely to continue.
The dips during a good run are associated with the RSI getting near or above 70 which means the asset is being overbought and a correction or trend reversal will soon occur most likely. As long as the crossover points stay positive, it will rebound, although no guarantee as to how much or if it will get back to the high point of the run. When the RSI is near 30, it signifies the asset is under bought and a price increase is likely coming, although if the crossovers are negative it is likely a short term jump which will be followed by more losses.
Because the rises and falls almost always follow very closely with them. Looking at the Fear/Greed index can give you an idea of how long the rises will last...
People say "Oh it's crypto, there are no rhyme or reason for rises and falls", but there are VERY clear signals that a rise or fall is going to occur and they are pretty accurate most of the time...not all the time but 90% of the time. And 90% will make you a lot of money.
Additionally Fibonacci retracements are vital for understanding key support levels...for instance there are 2 support levels right now that BTC is in the middle of...42K and 28K...these represent the next Fibonacci levels...if it continues trending down and breaks through the 28K level it might continue downward for a little bit until it skyrockets back up...conversely, if it makes it back to 42K there might not be another crash and it will continue upward until it challenges 48K which would be the next level up from there...
Mathematics plays a huge part in all of this and not understanding these models and sequences is akin to commiting investing suicide.