Twiggs Money Flow is a derivation of Chaikin Money Flow indicator, which is in turn derived from the Accumulation Distribution line.
However, Twiggs Money Flow makes two basic improvements to the Chaikin Money Flow formula:
1-To solve the problem with gaps, Twiggs Money Flow uses true range, rather than daily Highs minus Lows.
2-And, rather than a simple-moving-average-type formula, Twiggs Money Flow applies exponential smoothing, using the method employed by Welles Wilder for many of his indicators.