In reality, I measure neither risk nor reward, as a discretionary long only stock trader, after researching the target, I weigh up probabilities, which is vague because it's a guess too.
I'm more interested in something which in the long term will be a several bagger.
Frequently I'll enter a trade and it goes against me immediately or the following day.
So I target usually high risk, smaller cap, speculative positions including penny stocks and do so with multiple positions, I'm currently holding 85 different positions and I care not greatly about what any single position is doing once bought.
Like keys on a piano they move up and down constantly, over the long haul, I expect the portfolio to make progress.
The secrets are, you have to be in to win, you need exposure, one cannot second guess tomorrow because one minute to the next I have no idea which will gain and which will lose.
Diversify; for me these days I trade anything, yesterday was a goat milk infant powder company and had the perfect trade entering the bottom for the day and up 25% eod (yu gotta have a rarety good day sometimes). I'll hold this for months or more unless something stupid happens.
I prefer to buy bottom dwellers, if something has run hard I won't touch it, everything sooner or later pulls back, that's what I watch.
Today Thursday (asx not open yet) I'll add another small bite to a copper stock I have and which has pulled back.
I only need one of these stocks to blast up high and fast to make a big portfolio difference.
If any of my stocks go to zero, it's a small wound, and I've encountered this several times.