His name was Derek. Eleven years trading equities, a genuinely solid read of the market, and a 68% win rate that most traders would kill for. He opened four separate accounts to "diversify his approach" — one for swing trades, one for momentum, one for options, one for crypto. Within fourteen months, all four were margin-called. Not because his entries were wrong. Because he split his capital without adjusting his position sizing, and a correlated drawdown across all four accounts wiped him simultaneously.
Running multiple accounts isn't inherently dangerous — but it demands a complete rethink of your capital allocation maths. The core error Derek made is one of the most common: treating each account as independent when the risk is shared. If you're allocating $50,000 across four accounts — $12,500 each — and risking 2% per trade in every account, your true portfolio risk per correlated move is 2%, not 0.5%. The accounts are separate. The losses are not.
The maths that governs this is straightforward. Using fixed fractional position sizing, if total portfolio equity is $50,000 and your rule is 1% risk per trade, your maximum dollar risk per trade across all accounts combined is $500. Full stop. If you place two simultaneous trades across two accounts — one swing, one momentum — and they're in correlated assets, you've consumed your entire 1% allowance in a single market move. The formula is: Position Risk ($) = Total Portfolio Equity × Risk Fraction. That number doesn't change because you have four logins.
There are genuine advantages to the structure when the maths is respected. Segregating a speculative account from a core account protects compounding capital from high-variance strategies. Tax treatment across different account types — superannuation, company, personal — can be legitimately optimised with proper accounting. Strategy isolation also makes performance attribution cleaner: you can see exactly which approach is earning its keep. For traders wanting to explore the mechanics further, fixed ratio position sizing offers a scaling method suited to accounts with different equity levels, while Kelly Criterion provides a mathematical framework for optimal bet sizing across separate capital pools. Understanding how drawdown compounds against recovery requirements is what makes the difference between a multi-account structure that survives and one that collapses in the first correlated sell-off.
Multiple accounts won't save a trader who treats them as multiple chances to risk more. One portfolio. One risk budget. Everything else is just logistics.
This content is for educational purposes only and does not constitute financial product advice. Past performance is not indicative of future results. Profit Logic Ltd (ACN 688 669 936) accepts no responsibility for errors or omissions in this content or anywhere on this website. Always seek advice from a licensed financial adviser before making investment decisions.