My theory on this is: algo trading on short term, if it works you don’t tell anyone because by trading on the opportunity they decrease the available opportunity to you (efficient market, chaotic systems etc).
Long-term trading doesn’t work like this, in fact you want more people to identify the opportunity and buy to improve your position in the long term, but generally you should be investing on alternative signals not technical analysis.
In other words --- what you and I think isn't nearly as significant as what others are persuaded to think.
For example, I personally think TSLA is way, way, way over bought. The reasons for this are many and varied but still largely irrelevant. My opinion didn't stop an "analyst" from issuing a buy recommendation yesterday with a target price of $265.
Maybe this "analyst" has clear, logical reasoning with supporting computer analysis --- or maybe his grandma is just heavily bought into TSLA. In any case, the stock jumped 2.5% yesterday.
Bottom line --- everybody and his brother is using software. But opinion and psychology remain significant factors that defy computerization. The market can still stay irrational longer than you can stay solvent.
For one, if you wanted to make $20k per month, you'd need at least $200k invested. Oh wait, we're talking long term, not trading. In that case, you'll make about $20k per year. So you'd want $240k per year to pay that kind of salary, meaning you need around $2.4m in the bank.
It's a lot easier to raise that money by selling the tool than it would by trading the stocks.
It also doesn't hurt to share knowledge. Very often you can compare your notes to another.
In fact, if you had an algorithm that picked winning stocks, just add a little delay to everyone else's bots. Your bot buys it first, then some whale buys it and pumps your stock.
Long-term trading doesn’t work like this, in fact you want more people to identify the opportunity and buy to improve your position in the long term, but generally you should be investing on alternative signals not technical analysis.