Position sizing is the discipline of risking the same amount per trade as a fraction of account equity. M2M recommends risking no more than 1-2% of account equity per trade. R is the dollar amount you risk; R-multiples express trade outcomes as multiples of that risk (e.g., +2R = a winner worth twice your risked amount). All M2M signals are stated with explicit stops and 1R, 2R, 3R targets so position sizing is straightforward.
What good looks like
A trader with a $2,000 account risking $40 (2%) per trade with a 5% stop and 10% target. This is a 2R trade structure that lets a 50% win rate produce positive expectancy.
What not good looks like
A trader with a $2,000 account risking $400 (20%) per trade. Five consecutive losses (which happens often) cuts the account to $0. Position sizing prevents account blow-ups.