Size a Solana Perpetual From the Stop

Size a Solana perpetual by dividing the dollar loss you are willing to take by the distance between entry and stop, then adjust for costs that can widen the realized loss. For a linear contract quoted in US dollars, that distance multiplied by the SOL quantity gives the price loss before fees and funding.

This keeps the stop’s price level and the trade’s dollar risk in the same calculation.

How do you calculate SOL perpetual size from a stop?

Divide the planned risk budget by the entry-to-stop distance per SOL to get the maximum quantity before costs. For a long, subtract the stop price from the entry; for a short, subtract the entry from the stop. Use positive distances in both cases.

For example, a hypothetical long entered at $150 with a stop at $145 has a $5 distance. A $100 risk budget therefore allows 20 SOL before costs: 20 multiplied by $5 equals $100. At a $150 entry, that position has $3,000 notional exposure. The same quantity at a tighter stop would risk less; a wider stop would risk more.

• Set the risk budget in dollars before placing the trade.
• Choose the stop from the trade’s invalidation level, then measure its distance from the expected entry.
• Divide the budget by that distance to find the preliminary SOL quantity.
• Reduce the quantity to allow for fees, slippage and any funding you expect to pay.

The calculation assumes the position closes at the stop price. Flash Trade’s documentation describes stop orders as trigger-based and says execution can differ from the trigger during volatility or congestion. A stop is therefore an exit instruction, not a guaranteed maximum loss; a gap or thin order book can make the realized loss larger.

How should leverage and liquidation affect the size?

Leverage determines the collateral needed for a given notional position; it does not change the price loss per SOL between entry and stop. In the example, 20 SOL represents $3,000 of exposure at entry whether the trader posts more collateral or uses higher leverage. Higher leverage reduces the collateral supporting that exposure and can move liquidation closer to the stop.

Before submitting, compare the venue’s estimated liquidation price with the stop and check which price feed triggers each one. Kana Labs’ documentation says a stop should sit before liquidation in the adverse direction. If liquidation could occur first, lower leverage, add collateral or reduce the position so the planned exit has room to operate. The order panel’s estimate is specific to the venue’s margin rules and can change as the position or collateral changes.

What costs belong in the stop-risk estimate?

Fees, execution slippage and funding can all raise the cost of holding and closing a perpetual. Estimate the risk on the notional position, then reserve part of the budget for entry and exit fees and for a plausible difference between trigger and fill. If that allowance is material, reduce SOL quantity rather than treating the stop price as a guaranteed fill.

Funding matters most when the position remains open across settlement periods; its direction and rate depend on the market’s terms. For the overnight charge mechanics, see Byreal’s overnight funding calculation. Include an estimate of that cost when planning a longer hold, and recalculate if the funding rate or expected holding time changes.

The practical sequence is to choose the stop from the setup, size the position from the acceptable loss, then check margin and costs against that size. If the resulting position cannot sit beyond the liquidation price with a reasonable execution allowance, the trade is too large for the chosen stop and risk budget.