I voted to close this question as it is one of the most frequently asked question (on retail trading "platforms" like Reddit, quora and others). Some examples are 90-90-90 rule. Quora 1, Quora2, and it pops up there roughly ever 6 months. Reddit 1, Reddit 2.
People somehow perceive that they know something and can beat the market. Strictly speaking, if it were truly random, the best forecast would be yesterday's value. Hence, "trading" in itself is doomed. The reason a trader makes money for his/her firm is usually that they offer the service, for a charge (bid-ask, commission, fees..) and try not to be exposed to risk (market movements) as much as possible. Insofar, the "trader" is actually Robinhood et al. The users are just retail speculators (mainly).
Now, looking at the 90-90-90 rule, that means "90% of traders lose 90% of their money in 90 days". That is neither trading, nor investing. That is gambling. No sane investment manager buys and sells on a daily or weekly basis. Even (most) professionals, cannot beat the market, not even the most sophisticated firms. Their outcome looks a lot like this. Spoiler alert, good luck for finding periods or strategies that outperform the S&P500. In the words of Warren Buffett, "I have talked to huge pension funds, and I have taken them through the math, and when I leave, they go out and hire a bunch of consultants and pay them a lot of money. Just unbelievable." Tis is because he thinks any investment advice will be useless. He does not believe in EMH or random walks, but still suggests anyone to buy an index fund and never look at it again. His investment philosophy is to buy businesses and keep them "forever" (until he gets convinced that there are better businesses to own).
S&P Dow Jones Indices has good data. The Canadian example is an extreme outlier. As of Dec 31, 2020, 98.63% of funds underperformed the S&P/TSX Composite. However, US data does not look particularly good either. It’s bad and it’s getting worse when compared historically. There may be numerous reasons, but I suspect it is mainly that 50 years ago there was a lot less competition and it was a lot more difficulty to change your "investment" decision every 5 minutes without having internet.
The only players that tend to make money on short term bets are HFT traders. However, this is a vastly different type of "traders" compared to retail investors. This post has a good summary of some "basic" ideas to master for HFT. I think that is the only domain where you can consistently win but the users are like Lewis Hamilton. The best in their field, with the finest machinery on earth. Mainly, because you have a lot more data and the potential to exploit technological superiority. Compare FX tick data with +1 million quotes on any given day for liquid currency pairs vs 10 years of daily data. If you are in it for the long run, these ticks will be useless. If you have access to low latency of 20,000+ orders per second per single FIX, which is scalable to increase throughput and sub-millisecond roundtrip latency, the game will be different. InfoReach's website seems to be designed to Buffett's liking, no resources wasted to look pretty (although he would never need them).
However, their performance also is not stellar but looks more like a graveyard as Alex Gerko, the CEO of XTX puts it.
If you invest in sound stocks and predominantly indices, and buy and sell essentially only if you either have money to invest, or need money to spend, it is almost impossible to lose money. You may still not beat the S&P but you are not losing money either. Loosely speaking, if you buy because Tom Brady also likes crypto currency, or Mia Kalifa 1 likes Nokia and dogecoin Mia Khalifa 2 or someone else on Reddit claims Gamestop is unstoppable, you will be stopped. The same applies for a lot less silly decisions.