IMO most if not all of you are wasting your time. Markets spend 90% to 95% of the time in what I call bid/ask spread relative value efficient. That means that the only way to make money in that market regime at any given time, is to be an HFT/MMer with somewhat deep pockets to hedge and to smooth out bad statistics and "sell the noise" to chartists etc.
Of the other 5/10 % of the time that markets are outside their efficiency regime, it is almost always due to a news event. Therefore, strictly inputing price to predict the same instrument's price at a later time into any of these machine learning algorithms, which probably 9 or 10 out of 10 of you are doing, is going to lead you nowhere. You will feed these things data, it will spit out a model (probably a momentum model), you will trade it, but you will be driving Uber or collecting Social Security to actually pay your bills. If it spits out a MMing model, you will either get run over by a news event, or you will not be able to trade it because most retail traders aren't equipped to trade a MMing model.
Imo, the only edge left is either HFT/MMing (ruling out 99 out of 100 traders on ET), or understanding how news events affects different symbols. Doesn't mean you can't use machine learning to do news/price impact, but the database is not so easy to attain. News drives markets (the plural is important) out of efficiency for a non-trivial amount of time. Since news is essentially unpredictable, but markets rarely immediately know how to go to the efficiency regime instantly, this edge should "never" die even on say 15 minute time frames. Plenty of time.
You can play around with these algorithms if this is your hobby, but trying to make it a profession (actually being able to make a living trading ML models) is going to be nearly impossible in my experience.
FWIW.