[bluGill]

No.

First they ran in simulation, not the real market. It may be that that act of being in the market changes the market enough to make your strategy work. (though typically it is the opposite - things work in simulation but applying them to the market makes them not work). As such this paper doesn't really tell us anything useful.

Even if we ignore the above, they only tested a few different strategies. That says nothing about any other trading strategy that someone might apply: any of them might work.

I still think day trading is a bad way to invest, but this paper doesn't prove anything even though it speaks to my bias.

[bumby]

>things work in simulation but applying them to the market makes them not work

Can you elaborate? Is this because large flows of money eventually become the market? Insinuating that some strategies only work at low trade volume?

[bluGill]

Pretty much. When you trade any amount of money your trade is changing the market.

In some less honest markets there are even cases where what the numbers say you can trade isn't possible because those offering the deal won't follow through, or will let a friend in ahead of you