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Half & Double

Start with half. Double when right. Cut when wrong.

In a 27 February 2026 Morgan Stanley “Hard Lessons” interview, Stanley Druckenmiller, whose Duquesne Capital reportedly averaged about 30% a year with no losing year from 1981 to 2010, shared the biggest lesson he learned from George Soros: “It’s not whether you’re right or wrong, it’s how much you make when you’re right and how much you lose when you’re wrong.” He described buying a “not-big” Nvidia position, doubling it after ChatGPT appeared, then doubling again. ChartArmory’s Half & Double turns that sizing idea into a clear, mechanical price rule for TradingView.

$29.00One-time payment · Perpetual personal use

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What you get

Complete Pine Script v6 source
Install guide in 8 languages
Personal-use editing license · no redistribution or resale
30-day bug support
Copy button and ZIP after payment

Delivery & refund policy ↗

HALF & DOUBLE / HISTORICAL CASE

Half first, double on proof, ride the trend: Solana +329.2%, a real case

COINBASE:SOLUSD · 1D · 2023.09 → 2024.01+329.2%

Half at the 20-close breakout → ×2 at +1 ATR → sell all on the 3 ATR trailing stop · 0.1% cost per buy and per sell included

Before costs: +330.04%
Average of all 26 Solana trades · costs included: +24.48%

On the Coinbase Solana daily chart, the close of 20 September 2023 beat the previous 20-close high, so ½ bought half the account at the next open on 21 September ($20.30).

01 / Half buy2023.09.21$20.30½ · 20D CLOSE HIGH
02 / Double to full2023.10.01$21.36×2 · +1 ATR
03 / Sell all on the stop2024.01.08$89.52■ · 3 ATR · 109 D

Account change = value after the final sale ÷ value before the first buy − 1, with half the account buying at the first fill, the rest at the double fill, and 0.1% cost on every buy and sell.

Download the case data (JSON)

PROBLEM → FIX

These headaches, solved on your chart

Going all-in from the start, becoming a top detector, and getting stuck

Start light: a friendly ½ brake mark tells you to buy only half

Even in profit, frozen about when to add more

When price climbs 1 ATR more, a ×2 booster mark doubles the position

Recalculating a stop that changes every morning, head pounding

A 3 ATR defense line that follows the trend, drawn for you

01 / WHAT IT DOES

One price rule. Three clear steps.

1. Buy half on the breakout

When a daily close finishes above the highest close of the previous 20 candles, buy half (50% of your account) at the next candle’s open.

2. Double when proven right

When a close finishes 1 ATR (20-candle average true range) above your first fill, buy the other half at the next open to reach full size.

3. Exit on the trailing stop

When a close falls 3 ATR below the highest close since entry, sell everything at the next open.

03 / EVIDENCE

Historical test across 8 markets (2018–2026)

Daily data from 2018 with a 0.1% cost each side, comparing Half & Double with the same signals bought all-in and with simply holding. The half start did what it promises on losing trades: on Bitcoin the average losing trade was −8.3% against −10.4% all-in, and the worst single trade −15.0% against −26.5%.

Show the historical check

Daily data, 2018-01-01 to 2026-10-16 (crypto to 2026-10-18, Solana from its 2021 listing) · default 20 / ×2 at 1 ATR / 3 ATR stop · 0.1% cost per buy and per sell · annual rate (CAGR)
Market	Half & Double / yr	All-in / yr	Buy & hold / yr	Worst trade	Worst trade all-in	Deepest drop	Hold deepest drop
Bitcoin	+22.8%	+23.4%	+22.4%	−15.0%	−26.5%	−67.1%	−81.4%
Ethereum	+44.1%	+43.1%	+14.3%	−16.2%	−26.0%	−52.5%	−94.0%
Solana	+65.4%	+78.0%	+23.4%	−18.1%	−30.0%	−64.0%	−96.3%
Tesla	+27.0%	+22.0%	+38.1%	−18.7%	−31.1%	−51.0%	−73.6%
NVIDIA	+29.1%	+32.0%	+53.7%	−12.9%	−20.6%	−35.7%	−66.4%
Nasdaq Composite	+8.7%	+10.2%	+16.3%	−5.4%	−7.4%	−16.7%	−36.4%
S&P 500	+5.1%	+6.6%	+12.7%	−6.1%	−5.5%	−13.5%	−33.9%
Gold futures	+4.5%	+2.6%	+14.2%	−6.5%	−13.0%	−25.8%	−24.9%

WITHOUT THE INDICATOR

The disaster of going all-in on the first move

Daily 2018–2026 · 0.1% cost on each buy and sell · single trade

−26.5%

Bitcoin’s worst trade: All-in −26.5% → starting with half −15.0%

−30.0%

Solana’s worst trade: All-in −30.0% → starting with half −18.1%

04 / INSTALL

US$29 once: up and running in minutes

01Copy or download the code
02Paste into a new Pine indicator
03Add it to a daily chart

The defaults work as delivered. Change the lookback, first-buy %, double distance, stop distance, cost, start year and panel language in settings.

Past performance does not guarantee future results.

An independently coded tool inspired by the sizing lesson Stanley Druckenmiller described in public interviews, with ChartArmory’s own rule, chart display and scorecard. Not affiliated with or endorsed by Stanley Druckenmiller, George Soros or Duquesne, and he does not use this indicator.

HALF & DOUBLE / FAQ

Questions

Is this affiliated with Stanley Druckenmiller or George Soros?

No. This is independent work by ChartArmory. It is not affiliated with or endorsed by Stanley Druckenmiller or George Soros, and Druckenmiller does not use this indicator.

Does this indicator repaint?

No. Signals are calculated on closed candles and fills are modelled at the next candle’s open, so closed history never changes. During a live candle the pending decision can change until the candle closes.

Can I edit or share the code?

You can edit it for personal use. Sharing, redistribution and resale rights are not included.

HALF & DOUBLE · V1

Get Half & Double for a one-time US$29

One-time payment. Full Pine Script v6 source code, 8-language scorecard and install guide, and 30-day bug support, with no hype and every number on the table.

Delivery & refund policy ↗

$29.00One-time payment · Perpetual personal use

Add to my chart