Risk-Adjusted Position Sizing Across Multiple Prop Accounts: The Right Framework

The simplest trade copier setup copies 1 contract on the leader to 1 contract on every follower. Simple — and usually wrong. A $100K account and a $25K account copying the same 1-contract NQ position are not carrying the same risk. They're carrying the same dollar exposure but very different percentage exposure. Getting position sizing right across accounts of different sizes is the difference between a well-managed portfolio and an accidentally leveraged one.

The Core Principle: Percentage Risk, Not Dollar Risk

Define your risk per trade as a percentage of account size, not as a fixed dollar amount. The copier's job is then to translate that percentage into the correct contract count for each account, independently.

Example setup:

• Leader account: $100K — trades 2 NQ contracts — risk per trade: ~$500 = 0.5% of account
• Follower A: $100K — should copy 2 NQ contracts — same 0.5% risk
• Follower B: $50K — should copy 1 NQ contract — same 0.5% risk
• Follower C: $25K — should copy 2 MNQ contracts (micro equivalent) — same 0.5% risk
• Follower D: $25K evaluation — should copy 1 MNQ — more conservative, 0.25% risk at lower cushion

This is the correct framework. Each account carries proportionate risk to its size and stage — not arbitrary fixed contract counts.

The Contract Ratio Calculation

To calculate the correct ratio for each follower:

Follower ratio = (Follower account size / Leader account size) × Leader contract count

For a leader trading 2 NQ on a $100K account:

• $100K follower: (100K/100K) × 2 = 2 NQ
• $50K follower: (50K/100K) × 2 = 1 NQ
• $25K follower: (25K/100K) × 2 = 0.5 NQ → round down to 0, or convert: 5 MNQ (MNQ is 1/10th of NQ, so 0.5 NQ = 5 MNQ)

The MNQ conversion handles the case where proportionate sizing produces a fractional NQ contract — which doesn't exist. Switching the smaller account to micros gives you the granularity to maintain proportionate risk without rounding away half the position.

Adjusting for Account Stage

Account size alone isn't the only variable. An evaluation account in week one has a different risk profile than a funded account in its fourth payout cycle — not because the account size is different, but because the evaluation has lower risk tolerance (a mistake costs the evaluation fee) and the drawdown cushion is at its maximum.

A practical stage-based adjustment:

Configuring Ratios in Copilink

In Copilink, each follower account has an independent contract ratio setting. Configure each account's ratio according to the size-adjusted and stage-adjusted calculation above. The ratios can be updated at any time — as accounts move between stages or as cushion levels change, adjust the ratio accordingly.

For accounts that need cross-instrument mapping (NQ leader → MNQ follower), configure the instrument map alongside the ratio. Copilink applies both — it maps to the correct instrument and scales the contract count appropriately in a single configuration.

Review each account's ratio at the start of every new trading week. Account stages change, cushion levels fluctuate, new accounts join the pool. Five minutes of ratio review at the start of each week keeps the portfolio properly calibrated. More detail on the full risk framework at copilink.com/risk-management.