I'd like to see someone with anything but a large account make good money risking only 2%. It depends on account size, strategy, and more. Look below 2% of 10k = $200 2% of 100k = $2,000 If you have 100k or more then the 2% rule is probably reasonable. If you have 10k or less then it probably isn't. You have to factor in also the PROBABILITY of that loss. If you risk 5% with a 1% probability of loss this is much better then risking 2% with a 50% probability of loss. If you trade with a tiny account, it may be reasonable to risk even 20% of an account if the probability of that loss is very minuscule. I'd say the most you want to risk is around 8% per trade which provides for 12 losses in a row. But, it doesn't leave anything to trade with. Perhaps, you want to have 50% dd or less, that's 4% per trade. Even this analysis is rudimentary, it doesn't take into account what probability you have loss. Most working strategies have some small probability of significant loss.
Nobody can know the "probability of loss" (let alone the magnitude of the potential loss) on a particular trade. The correct mind-set for a trade is, "I think/believe the market will/should rise/decline from here... and I'm willing to risk ______ (%/points/tics) on my conclusion". That's it. Once the trade goes in your favor, then it becomes, (a) how much "room" do I allow for a counter before I stop out, or (b) where do I aggressively fade the move to take profits? Both are guesses.... which should be dictated by chart parameters.
At the time we enter a trade, we also enter a stop/loss level and a profit target for that position - in essence, three orders get entered to open a trade. The profit and stop/loss levels are dictated by the volatility and previous price action levels of the traded instrument - so we have a system that dictates meaningful profit and stop/loss levels. IMO, it is less than efficient (and possibly destructive, my 2 cents) to have a set percentage for either a stop or profit target. Having said that, I doubt those levels would ever exceed one-half of one percent for a trade. But again, it is dictated by the characteristics of the instrument being traded and not by an arbitrary value.