The Money flow oscillator is a technical indicator used to help predict price movement. It is calculated by averaging the highs, lows, and closing prices of a stock. It then multiplies that by the volume for the day.
When a stock is purchased on a higher price than it was it is considered an uptick. When it is purchased at a lower price than it once was it is considered a downtick.
If more shares are bought on an uptick then a downtick then flow if money is positive. If more shares are bought on a downtick then an uptick then flow of money is negative.
This can be used to confirm trend. If a stock is up trending while the money flow oscillator is in the positives it is good. If the line goes into the negatives it could be a sign the stock will turn around. Likewise if it turns positive while a stock is in a downtrend it could be a sign the stock will start to rise.