There's no such thing as 100% or even close to 100% knowledge of the market. Buffett will say that himself. He wouldn't invest in many sectors, simply because he didn't understand it well enough.
Now I'd like to ask you: Do you only invest in businesses that you have 100% knowledge in? If you open a profitable business with a partner, are you 100% sure he won't backstab you? Are you 100% sure that the someone else can't copy you and steal all your business? Nothing is guaranteed, but if you find enough great opportunities, you will come out far ahead even if some opportunities fail. You do your hishtadlus from before to minimize risk and maximize profitability and you pray to God on Rosh Hashana that you should be blessed with a good parnassah.
Ok, I really didn't mean to simply compare trading to gambling, I was just saying that just like when you gamble no matter how much effort you put into it it won't have an effect on the upcoming number/card etc, and you will win/loose based on a fact which you don't know, same here, you will definitely need to do research to figure which stock would be an earning one, "but" after all the companies earnings will be what it will be no matter how much research you did, and here
is where it's similar to gambling.
And regarding this;
"תלמוד בבלי ביצה דף ט"ז "כל מזונותיו של אדם קצובים לו מראש השנה ועד יום הכיפורים
you're 100+% right, I'm just talking b'derech ha'tavah, but we definitely goto have אמונה ובטחון and just pray to hashem for parnasah and then do the needed hishtadles.