Daily loss limit: reserve open risk before taking another trade

Choose one loss accounting policy

A policy can use net daily P&L, gross losing trades, marked equity decline or a trailing intraday peak. These are different rules. The worked example uses a fixed loss allowance from start-of-day equity, net realized losses already booked and remaining loss measured from current marks. Open P&L must be handled consistently so it is not omitted or counted twice.

Define the day boundary and timezone, especially in 24-hour markets. A clock reset does not flatten positions or erase their risk. Also decide whether realized profits increase the allowance. A conservative fixed-loss policy may decline to recycle profits; a net-P&L policy may permit it. Neither convention should change opportunistically after a losing trade.

Reserve what can still be lost

The admission calculation in this lesson is remaining budget = daily allowance − realized loss spent − modeled additional open loss − extra execution reserve. The open loss is incremental from the marks already included in the accounting baseline. If the baseline is marked equity instead of realized P&L, reconcile unrealized losses explicitly before using the same expression.

Specify what reaching the threshold does: reject new entries, cancel unfilled entry orders, or initiate reductions according to the plan. Cancelling an entry order does not close a position. A local alert is also not the same as an exchange-enforced control; loss can continue during latency, gaps or service outages.

Worked example: cash remaining is smaller than the headline limit

A hypothetical account starts at 10,000 USDT with a 300-USDT daily allowance. It has booked 120 of net realized losses, and two positions have no current unrealized P&L but modeled additional losses of 60 and 40. A separate 20-USDT execution reserve is not included in those position estimates. Remaining admission capacity is 300 − 120 − 60 − 40 − 20 = 60.

A new trade requesting 90 USDT of total modeled loss exceeds the remaining budget by 30. Cutting the quantity to fit must use actual contract increments and preserve its strategy invalidation; moving the stop arbitrarily closer merely to make the arithmetic fit changes the trade. If no valid order fits, the rule rejects it.

A new calendar day does not create risk-free capacity

If yesterday’s positions remain open after the reset, they still need a place in today’s risk accounting. Ignoring them while assigning the full fresh allowance to new trades compounds exposure. Likewise, a threshold-triggered market exit may fill after the loss has passed the threshold. Record both the trigger breach and final executed loss.