How many lots / shares?
Basic formula:
Position size = Account risk ÷ (Stop distance × value per pip/point)
Example (forex): Account $10,000, risk 1% = $100. Stop = 50 pips on EUR/USD. Standard lot pip value ≈ $10/pip (verify on your broker). Risk per pip for 0.1 lot ≈ $1. Need $100 ÷ 50 pips = $2/pip → roughly 0.2 lots (always confirm with broker calculator).
Never guess lot size. MT5: Tools → Options → or use built-in position size scripts/indicators.