Swan Noir really raises a point.
To consider loosing moeny in a trading business a failure, one also must be able to trade in the first place.
If I decide today - as a dude who loves cooking for himself a little - to open a start rated resturand and fuck up because my cooking is not good enough that is not a business failure for the restaurant, it is a moron thinking he can cook
So, to start trading as a business, one first has to be a trader or have a successfull trader. Learning a complex job while running a business doing this does not work in pretty much every area.
Want another one? I LVOE CARS. I love little sports cars.
Me opening a garage or tuning shop - and failing - would not be a failing business, it is a dude that is not a mechanic trying to make a mechanics job. Failure.
So, to be taken serious - trading as a business - start being a trader first place (sim and own personal side account successfull enough to be considered stable), then we can talk of the business side failing.
I consider trading as a business less risky than most other activieis, business wise. Assuming you have or are a good / decent trader... you dont have to deal with a lot of shit real businesses have, mostly this particular idiots called "customers" who demand to haggle about prices, delviery and contract details left and right. Your costs are pretty irrelevant - yes, it makes a difference whether you pay 100 or 200 USD per month for data, but it would be nearly as bad on your bottom line than the part time people demanding 50 cents more per hour because your margings are a LOT higher. Many businesses struggle to be net positive because they are in razor thin cost industries. You are mobile... you can trade worldwide, without in large scale regards to even language. You dont need expensive shop space (look at the rents in prime locations - and running a shop or restaurant location makes a difference). Trading is very simple as a business and a lof of unknown factors are just not there.
Heck, I have an on and off IT consulting business the last 20 years (there have been phases i just was not active) and man, the office politics and idiocy and price idiocy of larger projects is more than I can safely handle. A trading floor is a sane and calm environment compared to the combines moronity of some middle management in larger companies that you have to deal with because those morons ruin your project budget.
But still, for the question to make sense you msut remove all the wannabe idiots from it first. Trading as a business means you have to have a profitable trader in the first place. Otherwise it is not a business. Same way you dont open a resturant without a cook.