Why copied trades open at a different price than the master, and how to control slippage

Where the difference comes from

• Two brokers, two prices. The master and the follower usually trade at different brokers, or at least on different accounts. Each broker streams its own quotes with its own spread and markup, so the same instrument can show a slightly different bid and ask at the same moment.
• The market moves meanwhile. The follower’s order can only be sent after the master’s trade has happened. Between the master’s fill and the follower’s fill the price keeps moving, and in a fast market even a short delay shows up in the price.
• The follower’s broker executes it. Once the order is sent, the follower’s broker decides the fill. How quickly it answers and at which price depends on that broker, its execution type and the account.
• Spread at the moment of entry. A buy fills at the ask and a sell at the bid. If the follower’s spread is wider at that moment, its buy fills higher and its sell lower than the master’s.

Of these, only the time on our side is up to the copier. The follower orders go out as soon as the master’s trade is seen, priced with the last known quote, without waiting for a new tick. The rest of the way depends on the brokers.

What max slippage does

Max slippage is set in points, 50 by default. It is used in two places:

• With every order. It goes to the follower’s broker as the deviation the order accepts from the requested price. A broker that executes on request will requote rather than fill beyond it. Many brokers use market execution, where the order fills at the price available and the deviation may not apply: there the setting limits less.
• For late copies. When a trade is copied late, for example after the follower reconnects, it is only opened if the follower’s price is still within the max slippage of the master’s entry. A trade that has run away is skipped instead of chased.

After a requote or a price-changed answer, the copier tries again at once with a fresh price, up to three attempts in all.

A point is the smallest price step of the instrument, so 50 points is 5 pips on a five-digit currency pair, but a different distance on gold or an index. Check it against the instruments you trade.

Late copies at a better price

Sometimes a follower misses the moment: it was disconnected, or a trade was skipped for slippage. The copier compares the follower with the master every five minutes and after each reconnect, and opens the missing copy if the price allows it.

With Late copies also at a better price switched on, a late copy also opens when the follower would get a better entry than the master had: lower for a buy, higher for a sell. A copy that missed its entry can then still be taken when the market comes back.

Pending orders

A copied pending order sits at the same price level on the follower, so it fills at the follower’s broker when its own price reaches that level. That can be a moment earlier or later than the master’s fill, and sometimes the master’s order fills while the follower’s does not, because the follower’s price never quite got there.

For that case there is Market fallback for pending fills: when the master’s pending order has filled and the follower’s has not, the follower’s order is cancelled and the trade opened at market. It only happens near the master’s price, and only after the broker confirmed the cancel, so the follower never ends up with both.

Stop loss and take profit with different prices

Stop loss and take profit are not copied by default: the follower closes when the master closes. If you switch them on, the SL/TP calculation mode decides how they are placed:

Questions