Position Size Calculator with Fees

7月8日

# Position Size Calculator with Portfolio Management - Manual

## Overview

The Position Size Calculator with Portfolio Management is an advanced Pine Script indicator designed to help traders calculate optimal position sizes based on their total portfolio value and risk management strategy. This tool automatically calculates your risk amount based on portfolio allocation percentages and determines the exact position size needed while accounting for trading fees.

## Key Features

- **Portfolio-Based Risk Management**: Calculates risk based on total portfolio value
- **Tiered Risk Allocation**: Separates trading allocation from total portfolio
- **Automatic Trade Direction Detection**: Determines long/short based on entry vs stop loss
- **Fee Integration**: Accounts for trading fees in position size calculations
- **Risk Factor Adjustment**: Allows scaling of position size up or down
- **Visual Display**: Shows all calculations in a clear, color-coded table
- **Automatic Risk Calculation**: No need to manually input risk amount

## Input Parameters

### Total Portfolio ($)
- **Purpose**: The total value of your investment portfolio
- **Default**: 0.0
- **Range**: Any positive value
- **Step**: 0.01
- **Example**: If your total portfolio is worth $100,000, enter 100000

### Trading Portfolio Allocation (%)
- **Purpose**: The percentage of your total portfolio allocated to active trading
- **Default**: 20.0%
- **Range**: 0.0% to 100.0%
- **Step**: 0.01
- **Example**: If you allocate 20% of your portfolio to trading, enter 20

### Risk from Trading (%)
- **Purpose**: The percentage of your trading allocation you're willing to risk per trade
- **Default**: 0.1%
- **Range**: Any positive value
- **Step**: 0.01
- **Example**: If you risk 0.1% of your trading allocation per trade, enter 0.1

### Entry Price ($)
- **Purpose**: The price at which you plan to enter the trade
- **Default**: 0.0
- **Range**: Any positive value
- **Step**: 0.01

### Stop Loss ($)
- **Purpose**: The price at which you will exit if the trade goes against you
- **Default**: 0.0
- **Range**: Any positive value
- **Step**: 0.01

### Risk Factor
- **Purpose**: A multiplier to scale your position size up or down
- **Default**: 1.0 (no scaling)
- **Range**: 0.0 to 10.0
- **Step**: 0.1
- **Examples**:
- 1.0 = Normal position size
- 2.0 = Double the position size
- 0.5 = Half the position size

### Fee (%)
- **Purpose**: The percentage fee charged per transaction
- **Default**: 0.01% (0.01)
- **Range**: 0.0% to 1.0%
- **Step**: 0.001

## How Risk Amount is Calculated

The script automatically calculates your risk amount using this formula:

```
Risk Amount = Total Portfolio × Trading Allocation (%) × Risk % ÷ 10,000
```

### Example Calculation:
- Total Portfolio: $100,000
- Trading Allocation: 20%
- Risk per Trade: 0.1%

**Risk Amount = $100,000 × 20 × 0.1 ÷ 10,000 = $20**

This means you would risk $20 per trade, which is 0.1% of your $20,000 trading allocation.

## Portfolio Structure Example

Let's say you have a $100,000 portfolio:

### Allocation Structure:
- **Total Portfolio**: $100,000
- **Trading Allocation (20%)**: $20,000
- **Long-term Investments (80%)**: $80,000

### Risk Management:
- **Risk per Trade (0.1% of trading)**: $20
- **Maximum trades at risk**: Could theoretically have 1,000 trades before risking entire trading allocation

## How Position Size is Calculated

### Trade Direction Detection
- **Long Trade**: Entry price > Stop loss price
- **Short Trade**: Entry price < Stop loss price

### Position Size Formulas

#### For Long Trades:
```
Position Size = -Risk Factor × Risk Amount / (Stop Loss × (1 - Fee) - Entry Price × (1 + Fee))
```

#### For Short Trades:
```
Position Size = -Risk Factor × Risk Amount / (Entry Price × (1 - Fee) - Stop Loss × (1 + Fee))
```

## Output Display

The indicator displays a comprehensive table with color-coded sections:

### Portfolio Information (Light Blue Background)
- **Portfolio (USD)**: Your total portfolio value
- **Trading Portfolio Allocation (%)**: Percentage allocated to trading
- **Risk as % of Trading**: Risk percentage per trade

### Trade Setup (Gray Background)
- **Entry Price**: Your specified entry price
- **Stop Loss**: Your specified stop loss price
- **Fee (%)**: Trading fee percentage
- **Risk Factor**: Position size multiplier

### Risk Analysis (Red Background)
- **Risk Amount**: Automatically calculated dollar risk
- **Effective Entry**: Actual entry cost including fees
- **Effective Exit**: Actual exit value including fees
- **Expected Loss**: Calculated loss if stop loss is hit
- **Deviation from Risk %**: Accuracy of risk calculation

### Final Result (Blue Background)
- **Position Size**: Number of shares/units to trade

## Usage Examples

### Example 1: Conservative Long Trade
- **Total Portfolio**: $50,000
- **Trading Allocation**: 15%
- **Risk per Trade**: 0.05%
- **Entry Price**: $25.00
- **Stop Loss**: $24.00
- **Risk Factor**: 1.0
- **Fee**: 0.01%

**Calculated Risk Amount**: $50,000 × 15% × 0.05% ÷ 100 = $3.75

### Example 2: Aggressive Short Trade
- **Total Portfolio**: $200,000
- **Trading Allocation**: 30%
- **Risk per Trade**: 0.2%
- **Entry Price**: $150.00
- **Stop Loss**: $155.00
- **Risk Factor**: 2.0
- **Fee**: 0.01%

**Calculated Risk Amount**: $200,000 × 30% × 0.2% ÷ 100 = $120
**Actual Risk**: $120 × 2.0 = $240 (due to risk factor)

## Color Coding System

- **Green/Red Header**: Trade direction (Long/Short)
- **Light Blue**: Portfolio management parameters
- **Gray**: Trade setup parameters
- **Red**: Risk-related calculations and results
- **Blue**: Final position size result

## Best Practices

### Portfolio Management
1. **Keep trading allocation reasonable** (typically 10-30% of total portfolio)
2. **Use conservative risk percentages** (0.05-0.2% per trade)
3. **Don't risk more than you can afford to lose**

### Risk Management
1. **Start with small risk factors** (1.0 or less) until comfortable
2. **Monitor your total exposure** across all open positions
3. **Adjust risk based on market conditions**

### Trade Execution
1. **Always validate calculations** before placing trades
2. **Account for slippage** in volatile markets
3. **Consider position size relative to liquidity**

## Risk Management Guidelines

### Conservative Approach
- Trading Allocation: 10-20%
- Risk per Trade: 0.05-0.1%
- Risk Factor: 0.5-1.0

### Moderate Approach
- Trading Allocation: 20-30%
- Risk per Trade: 0.1-0.15%
- Risk Factor: 1.0-1.5

### Aggressive Approach
- Trading Allocation: 30-40%
- Risk per Trade: 0.15-0.25%
- Risk Factor: 1.5-2.0

## Troubleshooting

### Common Issues

1. **Position Size shows 0**
- Verify all portfolio inputs are greater than 0
- Check that entry price differs from stop loss
- Ensure calculated risk amount is positive

2. **Very small position sizes**
- Increase risk percentage or risk factor
- Check if your risk amount is too small for the price difference

3. **Large risk deviation**
- Normal for very small positions
- Consider adjusting entry/stop loss levels

### Validation Checklist
- [ ] Total portfolio value is realistic
- [ ] Trading allocation percentage makes sense
- [ ] Risk percentage is conservative
- [ ] Entry and stop loss prices are valid
- [ ] Trade direction matches your intention

## Advanced Features

### Risk Factor Usage
- **Scaling up**: Use risk factors > 1.0 for high-confidence trades
- **Scaling down**: Use risk factors < 1.0 for uncertain trades
- **Never exceed**: Risk factors that would risk more than your comfort level

### Multiple Timeframe Analysis
- Use different risk factors for different timeframes
- Consider correlation between positions
- Adjust trading allocation based on market conditions

## Disclaimer

This tool is for educational and planning purposes only. Always verify calculations manually and consider market conditions, liquidity, and correlation between positions. The automated risk calculation assumes you're comfortable with the mathematical relationship between portfolio allocation and individual trade risk. Past performance doesn't guarantee future results, and all trading involves risk of loss.

6 天前

發行說明

Position Size Calculator with Fees - User Manual

Overview
The Position Size Calculator is a Pine Script v6 indicator designed to help traders calculate the optimal position size for their trades while accounting for trading fees. It automatically determines whether you're planning a long or short trade and applies the appropriate formula.

Key Features
- Automatic Trade Detection: Detects long/short trades based on entry vs stop loss prices
- Fee Integration: Incorporates trading fees into position size calculations
- Visual Display: Shows all calculations in an easy-to-read table
- Real-time Updates: Recalculates as you adjust input parameters
- Historical Reference: Plots position size over time for analysis

Input Parameters

Required Inputs
- Entry Price ($): The price at which you plan to enter the trade
- Stop Loss ($): The price at which you'll exit if the trade goes against you
- Risk ($): The maximum amount of money you're willing to lose on this trade

Optional Inputs
- Risk Factor: Multiplier for your risk amount (default: 1.0)
- Use 0.5 for half position, 2.0 for double position, etc.
- Fee (%): Trading fee percentage (default: 0.01%)
- Enter as percentage (e.g., 0.1 for 0.1%)

How It Works

Trade Direction Detection
The indicator automatically determines your trade direction:
- LONG Trade: Entry Price < Stop Loss Price
- SHORT Trade: Entry Price > Stop Loss Price

Position Size Formulas

For Long Trades:

Position Size = (Risk Factor × Risk $) ÷ [Stop Loss × (1 - Fee%) - Entry Price × (1 + Fee%)]

For Short Trades:

Position Size = (Risk Factor × Risk $) ÷ [Entry Price × (1 - Fee%) - Stop Loss × (1 + Fee%)]

Fee Calculation
Fees are applied to both entry and exit:
- Entry: You pay fee when buying/selling to enter
- Exit: You pay fee when closing the position
- Long trades: Buy at entry (pay fee), sell at stop loss (receive less due to fee)
- Short trades: Sell at entry (receive less due to fee), buy at stop loss (pay fee)

Visual Interface

Information Table
Located in the top-right corner, displays:
- Trade Type: LONG (green), SHORT (red), or INVALID (gray)
- Entry Price: Your specified entry price
- Stop Loss: Your specified stop loss price
- Fee (%): Applied trading fee
- Risk Amount: Maximum risk in dollars
- Risk Factor: Position size multiplier
- **Effective Entry: Entry price after fees
- **Effective Exit: Exit price after fees
- **Position Size: Calculated position size (highlighted in blue)

Usage Examples

Example 1: Long Trade
- Entry Price: $100
- Stop Loss: $95
- Risk: $50
- Fee: 0.1%

Calculation:
- Effective Entry: $100 × 1.001 = $100.10
- Effective Exit: $95 × 0.999 = $94.90
- Risk per Share: $100.10 - $94.90 = $5.20
- Position Size: $50 ÷ $5.20 = 9.62 shares

Example 2: Short Trade
- Entry Price: $100
- Stop Loss: $105
- Risk: $50
- Fee: 0.1%

Calculation:
- Effective Entry: $100 × 0.999 = $99.90
- Effective Exit: $105 × 1.001 = $105.11
- Risk per Share: $99.90 - $105.11 = -$5.21
- Position Size: $50 ÷ $5.21 = 9.59 shares

Best Practices

Input Validation
- Ensure Entry Price and Stop Loss create a valid trade direction
- Risk amount should be meaningful relative to your account size
- Fee percentage should match your broker's actual fees

Risk Management
- Never risk more than 1-2% of your account on a single trade
- Use the Risk Factor to scale positions up or down
- Consider slippage in addition to stated fees

Position Sizing Strategy
- Conservative: Risk Factor 0.5-1.0
- Standard: Risk Factor 1.0
- Aggressive: Risk Factor 1.5-2.0

Troubleshooting

Common Issues

Position Size Shows 0
Causes:
- Invalid trade setup (entry price equals stop loss)
- Risk per share is negative or zero
- Fees make the trade unprofitable

Solutions:
- Check that entry and stop loss prices create a valid long or short setup
- Reduce fee percentage if it's too high
- Increase distance between entry and stop loss

"INVALID" Trade Type
Cause: Entry price equals stop loss price
Solution: Adjust either entry or stop loss to create a clear direction

Unrealistic Position Sizes
Causes:
- Very small risk per share
- Very large risk amount
- Incorrect fee calculation

Solutions:
- Increase stop loss distance
- Reduce risk amount
- Verify fee percentage is correct

Advanced Features

Risk Factor Applications
- Scale In: Use 0.5 for initial position, 0.25 for additional entries
- High Conviction: Use 1.5-2.0 for strong setups
- Paper Trading: Use 0.1 for practice with small sizes

Important Notes

Limitations
- Does not account for slippage
- Assumes fees are percentage-based (not fixed)
- Does not consider margin requirements
- Position sizes are theoretical until executed

Risk Warnings
- Always verify calculations manually for large trades
- Consider market liquidity when sizing positions
- Account for overnight gaps and weekend risk
- This tool is for educational purposes only

Support and Updates
This indicator is designed to be simple and reliable. If you encounter issues:
1. Verify all input parameters are reasonable
2. Check that your trade setup is valid (long or short)
3. Ensure fee percentages match your broker's actual fees

Remember: Position sizing is just one component of successful trading. Always combine with proper risk management, market analysis, and emotional discipline.