Running two bots on one account without them fighting

Adding a second strategy feels like diversification. On a separate account it usually is. On the same account it is a new, untested strategy made of two parts, and the parts share everything that matters: margin, equity, and the drawdown limit you set for one of them.

Magic numbers are the minimum, not the solution

Every EA tags its orders with a magic number so it only manages its own. Two bots sharing a magic number will close each other's trades, move each other's stops, and produce a history that makes no sense. Give each one a distinct number before anything else, and confirm it by opening one trade from each and checking the comment and magic columns.

That solves ownership. It solves nothing about risk.

Margin is a shared pool

Bot A does not know Bot B exists. If both size positions as a percentage of free margin, each one's calculation is wrong the moment the other has trades open. When A is deep in a floating loss, B silently starts trading smaller. When A closes, B jumps back to full size, often right after the volatility that caused the drawdown.

Two bots on one account are not two strategies. They are one strategy you never tested.

Correlation stacks the real exposure

A gold bot and a "USD basket" bot are frequently the same directional bet with different labels. So are two bots on EURUSD and GBPUSD, most of the time. The number that matters is not how many strategies you run, it is how much you lose when the correlated ones are all wrong at once. Add the worst-case exposure of both, in dollars, and compare it to the account.

• Write down each bot's maximum simultaneous positions and lot size
• Convert both to a dollar risk figure at their stop levels
• Assume they trigger on the same day, because eventually they will
• If that total is more than you would accept from a single bot, reduce both

Fixed lots make the maths honest

Percentage sizing is fine on a single-strategy account. On a shared one, fixed lots per bot, sized for the combined worst case, are far easier to reason about. You give up some compounding and get a portfolio whose limits you can actually calculate.

One terminal or two?

Two EAs in one terminal on separate charts is normal and fine. Two terminals logged into the same account is where things break: both send orders, neither sees a consistent picture, and grid or hedge systems can double their exposure without either one being at fault. If you want isolation, use a second account, not a second terminal.

Keep a plain record

A short note with each bot's name, magic number, symbol, lot size and daily limit takes five minutes to write and saves an evening of confusion three months later, when you have forgotten which one places the trades that hold overnight.