How to Copy ES Trades to MES Accounts: Contract Ratio Setup in NinjaTrader

ES (E-mini S&P 500) and MES (Micro E-mini S&P 500) are the same underlying instrument at different scales. MES is exactly 1/10th the size of ES — one ES contract is equivalent to 10 MES contracts in terms of notional exposure. Copying from an ES leader to MES follower accounts is a common setup for prop traders who have larger-funded accounts trading ES and smaller evaluation or early-funded accounts that should trade MES to keep risk proportionate.

The Ratio Explained

ES tick value: $12.50 per tick ($0.25 index point move).
MES tick value: $1.25 per tick (same move).
Ratio: 10 MES = 1 ES in notional terms.

If your leader trades 1 ES contract, followers that should carry equivalent exposure need 10 MES contracts. If followers should carry half the exposure (proportionate to a smaller account), they need 5 MES.

Setting Up the Instrument Map in Copilink

In Copilink, open the follower account settings for each account that should trade MES instead of ES:

1. Leader instrument: ES [current contract] (e.g., "ES 09-26" for September 2026 expiry)
2. Follower instrument: MES [current contract] (e.g., "MES 09-26" — matching expiry month)
3. Contract ratio: Set based on the follower account's size relative to the leader

Example configurations:

• $100K follower copying $100K leader: Map ES → MES at 10:1 (full equivalent)
• $50K follower copying $100K leader: Map ES → MES at 5:1 (half equivalent)
• $25K evaluation copying $100K leader: Map ES → MES at 2:1 or 3:1 (conservative, proportionate to account size and evaluation stage)

Contract Rollover

ES and MES follow the CME quarterly expiry schedule: March (H), June (M), September (U), December (Z). Approximately one week before expiry, volume migrates to the next contract. You need to update both sides of the instrument map at rollover:

1. Update the leader instrument from "ES 09-26" to "ES 12-26"
2. Update the follower instrument from "MES 09-26" to "MES 12-26"
3. Verify the map is working with a test entry before live trading on the new contract

NinjaTrader will throw an error if you try to copy to an instrument with no active contract (which happens if the old front-month has expired and hasn't been rolled). The error is your signal that rollover is needed.

Mark the quarterly rollover dates in your calendar: typically the second week of March, June, September, and December.

Stop Loss and Target Translation

When copying ES stops to MES followers, the copier translates the stop price in the correct instrument. A stop at ES 5,200.00 copies as a stop at MES 5,200.00 — same price level, different instrument, same tick structure. The price reference is preserved; only the dollar value per tick changes (which is already accounted for by the contract ratio).

One thing to verify in testing: bracket orders (OCO stops and targets) should replicate correctly to MES followers with both legs intact. Run a full test with an entry, stop, and target on the leader and verify the complete bracket appears correctly on the MES follower before trading live. The full cross-instrument setup is supported in Copilink — details at copilink.com/faq.