Pine Script Daily Kill Switch for Prop Firms

Tracks session P&L and blocks new entries once losses hit your configured threshold. The most important prop firm safety mechanism in any automated strategy.

Copy//@version=5
strategy("Daily Kill Switch", overlay=true)

// ── Inputs ──────────────────────────────────────────────
dailyLossLimit = input.float(-800.0, "Daily Loss Limit ($)", step=50,
     tooltip="Strategy stops new entries when session P&L hits this level. Set to 80% of firm's daily limit.")

// ── State ────────────────────────────────────────────────
var float sessionPnL   = 0.0
var bool  killActive   = false

// Reset at each session open
if session.isfirstbar_regular
    sessionPnL  := 0.0
    killActive  := false

// Accumulate closed-trade P&L within the session
if strategy.closedtrades > strategy.closedtrades[1]
    sessionPnL += strategy.closedtrades.profit(strategy.closedtrades - 1)

// Activate kill switch when threshold is breached
if sessionPnL <= dailyLossLimit
    killActive := true

// ── Entry logic (replace with your own conditions) ───────
longCondition  = ta.crossover(ta.ema(close, 9), ta.ema(close, 21)) and not killActive
shortCondition = ta.crossunder(ta.ema(close, 9), ta.ema(close, 21)) and not killActive

if longCondition
    strategy.entry("Long", strategy.long)
    strategy.exit("Long Exit", "Long", profit=20, loss=10)

if shortCondition
    strategy.entry("Short", strategy.short)
    strategy.exit("Short Exit", "Short", profit=20, loss=10)

// Visual indicator
bgcolor(killActive ? color.new(color.red, 90) : na, title="Kill Switch Active")

How it works

The snippet maintains two persistent variables using Pine Script's var keyword: sessionPnL (a running total of closed-trade profit/loss for the session) and killActive (a boolean flag that gates all entry conditions).

Each time a trade closes — detected by comparing strategy.closedtrades to its previous value — the profit from that trade is added to sessionPnL. Once sessionPnL drops to or below dailyLossLimit, the killActive flag is set to true. From that point forward, both the long and short entry conditions include and not killActive, which blocks any new entries for the rest of the session.

The chart background turns red when the kill switch is active, giving you an immediate visual confirmation that no more trades will fire that day.

How to configure it for your firm

Set dailyLossLimit to 80% of your firm's stated daily loss cap. This gives you a buffer before hitting the hard floor and leaves room for any slippage or fill variance on open positions.

Frequently Asked Questions

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