Knowledge · Terms · MFI

MFI

Indicator indicator
Money Flow Index
Like RSI, but volume-weighted: a 0–100 oscillator that measures buying pressure (money in) against selling pressure (money out). Often called the „volume-weighted RSI“.

What is the MFI?

By Gene Quong & Avrum Soudack. The Money Flow Index combines price and volume into a 0–100 oscillator — essentially an RSI whose moves are weighted by volume.

Typical Price = (high + low + close) / 3
Raw Money Flow = Typical Price · volume
Money Ratio = Σ(positive RMF, N) / Σ(negative RMF, N)
MFI = 100 − 100 / (1 + Money Ratio)

("Positive" = typical price higher than the previous period, otherwise "negative".)

Interpretation

  • > 80 overbought, < 20 oversold (tighter extreme zones than is usual for RSI).
  • Divergences to price count as strong because volume flows into them.

How Botty uses the MFI

  • Filter mfi_pifagor_filter (strategies/conditions/filters.py, Pifagor): uses a recentered MFI(14) with a range of ~[−50, +50]. Long passes when mfi_pifagor is above the long threshold (green zone, default > −9), short analogously.

MFI vs. related indicators

  • vs. RSI: identical idea, but MFI weights by volume → reacts differently at volume spikes.
  • vs. OBV/CMF: all three are volume-flow measures, but OBV is cumulative-binary, CMF uses the intra-bar position, MFI is a bounded oscillator.