Indices copy trading: US30, NAS100, SPX500 and GER40

How index copying works

Index trades are copied like any other position: the source opens, the copier maps the symbol, sizes the trade, applies your filters and sends the order; later partial closes and stop changes are followed. What is different is the instrument itself. Index CFDs are defined by each broker, so two brokers can list the same index with different contract sizes, lot steps, trading hours and even different underlying (cash index or futures).

Before you copy indices, open the symbol specification on both accounts once and compare contract size, minimum lot and lot step. Those three numbers decide which sizing mode is safe.

Why contract sizes differ, and why it matters

With risk by balance, lot multiplier or fixed lot, the copier copies a number of lots. If the source's US30 is $1 per point and yours is $10, the follower carries ten times the intended risk. Risk percent avoids this: it uses your broker's tick value to work out how many lots make the stop cost exactly your chosen share of balance.

If you must mirror lots, divide the multiplier by the contract ratio (0.1 in the example above) and add a max lot cap. Check the result with a test trade before you go live.

Minimum lots and lot steps

Some brokers only allow index lots in steps of 0.1 or 1.0. The copier always rounds down to your broker's lot step, so it never risks more than calculated. When the calculated size is below the minimum lot, the default is to open the minimum, which can be more risk than you asked for on a small account. Turn that off if you would rather skip the trade.

Cash sessions, gaps and dividends

Most index CFDs trade nearly 23 hours a day, but liquidity follows the underlying exchange. Spreads are tightest during the cash session (US indices: 14:30–21:00 UTC in northern winter, an hour earlier in summer) and widen sharply outside it. The cash open itself often gaps; a copied market order at 14:30:00 can fill several points away from the source.

Cash-index CFDs are adjusted for dividends: on ex-dividend days, a cash adjustment is booked on open positions. Long positions are debited and shorts credited, or the reverse, depending on the broker's terms. Swaps are charged nightly.

A time filter that skips the first minutes after the cash open is a simple way to avoid the worst fills if your source trades the open.

Index symbol mapping

The copier knows the common aliases: US30 ↔ DJ30 ↔ WS30 ↔ US30Cash, NAS100 ↔ USTEC ↔ US100, SPX500 ↔ US500 ↔ SP500, GER40 ↔ DE40 ↔ DAX (including the older GER30/DE30 names), UK100 ↔ FTSE100 and JPN225 ↔ JP225. Suffixes such as .cash, .f or + are stripped.