If you’re trading at 50% scale with no stop loss on an underlying $100,000 strategy, and the strategy takes a loss of $10,000 on a trade (which represents a 10% loss on the unscaled strategy), does your position take a prorated $5,000 loss (10% of scaled position) or the full $10,000?
Autotrade “scaling” works for both the opening and closing of positions (regardless of “why” a trade is closed – i.e. regardless of whether a trade is “stopped out” or just simply closed).
So, to use your example, let’s say the Model Account of a strategy does this:
Buy 4 contracts at $5,000 per contract
Sell 4 contracts at $2,500 per contract
== Loss of $10,000 in the Model Account
Now assume you are trading at 50% scaling in your AutoTrade brokerage account. You will see something like this:
Buy 2 contracts at $5,000 per contract
Sell 2 contracts at $2,500 per contract
== Loss of $5,000 in your real brokerage account
Standard caveats apply: You may get slightly different prices than the Model Account, depending on market conditions, and so your own P/L may be slightly worse or better. But the general idea applies.
