MFI (Money Flow Index)

The MFI is essentially RSI weighted by volume. It oscillates between 0 and 100, with readings above 80 suggesting overbought and below 20 suggesting oversold conditions.

Declaration

function init(ctx) {
  ctx.indicator('mfi', 'MFI', { period: 14 });
}

Options

Output

Returns a single number[] series with values between 0 and 100.

Accessing Values

function onBar(ctx, i) {
  const mfi = ctx.ind.mfi[i];
}

Use Cases

Overbought / Oversold with Volume Confirmation

function onBar(ctx, i) {
  const mfi = ctx.ind.mfi[i];
  
  // MFI accounts for volume, so signals carry more weight than RSI alone
  if (mfi < 20) {
    ctx.order.market('ASSET', 1, { signal: 'buy', reason: 'mfi_oversold' });
  }
  if (mfi > 80) {
    ctx.order.close('ASSET', { signal: 'sell', reason: 'mfi_overbought' });
  }
}

MFI + RSI Comparison

function init(ctx) {
  ctx.indicator('rsi', 'RSI', { period: 14 });
  ctx.indicator('mfi', 'MFI', { period: 14 });
}

function onBar(ctx, i) {
  const rsi = ctx.ind.rsi[i];
  const mfi = ctx.ind.mfi[i];
  
  // Both signaling oversold = stronger signal
  if (rsi < 30 && mfi < 20) {
    ctx.order.market('ASSET', 1, { signal: 'buy', reason: 'rsi_mfi_double_oversold' });
  }
}

Calculation

1. Typical Price = (High + Low + Close) / 3
2. Money Flow = Typical Price x Volume
3. Positive/Negative flows separated by direction
4. Money Flow Ratio = Positive Flow / Negative Flow
5. $MFI = 100 - \frac{100}{1 + MFR}$

Related

• RSI - Price-only momentum oscillator
• OBV - Cumulative volume indicator
• VWAP - Volume Weighted Average Price