Trailing drawdown and gold volatility: a sizing formula

[FXS London Scalper]

A trailing drawdown moves up with your account's high water mark. Combined with gold's volatility, it can end accounts fast if sizing doesn't account for it.

How trailing drawdown works:
- Starting balance: $100,000. Max drawdown: $5,000. Floor: $95,000.
- Account reaches $103,000. Floor moves to $98,000.
- Remaining buffer: always $5,000 from the peak, regardless of profit made.

Sizing formula for gold:
Max risk per trade = (current equity - floor) / number of losses you want to survive

If buffer is $5,000 and you want to survive 8 consecutive losses: $625 per trade.
With a $3.00 stop on 100 oz contracts: $625 / $300 per lot = 2.08 lots → 2 lots.

As profit grows, the floor rises, but the buffer doesn't grow. So risk per trade stays the same in dollars.

On gold specifically: volatility spikes can produce several stop-outs quickly. Sizing for more consecutive losses (e.g. 10) adds safety.

How do you size gold trades under trailing drawdown?