All assets have a risk/return combination that can me regressed to the security market line. A theoretical concept.
Not including leverage, most have returns in single digits. Additionally, trading strategies are merely buy/sell optimizations around an asset's expected return. Therefore, strategy returns will be highly correlated to that assets return.
You may not be using financial leverage, but you are using some kind of leverage. In a stock trader's case, the trader would have to load up on a ton of Beta that is many multiples of the market. If the market, Beta 1, can loose 50% in a given year then catastrophic loss becomes an eventuality.
We could keep thinking that we have that special something (superior timing or selection) that would allows us to be that 1% trader. But, bare in mind that legendary figures are documented to make only 20-30% a year for 10 years straight.
A trader has to recheck their return assumptions and know how they are generating excess returns. That will also give them an idea of possible losses.