How many shares do I need to sell at my target to make the rest of my position risk-free?

How this is calculated

• Risk per share is the distance between your entry price and your stop-loss price. Profit per share at your target is the distance between your entry price and your target price.
• Total dollar risk on the full position equals risk per share multiplied by total shares. Shares to sell at target equals total dollar risk divided by profit per share at target, rounded up to the next whole share so the sale fully covers the original risk.
• This assumes that once you sell the calculated shares at your target, you move the stop on the remaining "runner" shares to your entry price (breakeven). At that point, the worst case on the runner is a scratch, not a loss, ignoring commissions and slippage.
• If the shares to sell at target would be more than your total position, your target is too close to your entry relative to your stop distance to fully self-insure the trade with a single partial exit. You would need a wider target, a tighter stop, or a different plan.
• This is a mechanical, math-only calculation of a common scaling technique. It doesn't account for slippage, commissions, or a stop failing to fill at your intended breakeven price during a fast move.