A money manager running thirty investor accounts has a simple arithmetic problem: placing every trade thirty times is impossible to do accurately and impossible to do at speed. MAM solves it by letting the manager trade once and having the system do the distribution.
How allocation works
The manager trades on a master account. The system then allocates that trade across the managed investor accounts, sizing each according to a configured method:
- By balance — each account receives volume proportional to its balance.
- By equity — proportional to current equity, so open positions affect sizing.
- By fixed ratio — a defined proportion per account, independent of size.
- By lot — a specified volume per account.
Method choice is not cosmetic. Balance-based allocation and equity-based allocation diverge as soon as accounts carry open positions, and the difference compounds. The manager should understand which they are using.
What investors keep
Under MAM, every investor retains their own trading account, their own balance and their own statement. They can see precisely what was traded on their behalf. The manager receives execution rights — the ability to trade the account — not ownership of it.
This separation is what makes MAM comfortable for investors who want professional management without handing over custody of their funds.
What a broker needs to support it
- 1A master account structure linked to the managed set.
- 2Configurable allocation methods per manager mandate.
- 3Permission controls defining what a manager may and may not do.
- 4Management and performance fee handling.
- 5Reporting at both manager and investor level.
- 6Correct handling of partial fills and partial closes across the allocation.
That last point is where implementations most often fall short. A partially filled master order has to be distributed proportionally, not assigned arbitrarily, or the allocation stops matching the mandate.
See MAM allocation on sample data
The demo shows a manager view with investor allocations side by side.