x[t] - x[t-k], TA-Lib's MOM. Mathematically identical to Diff(k).
Lookback k. TA-Lib defaults to 10.
Warmup behaviour: 'strict' (NaN until full window), 'expanding' (use partial windows), or 'zero' (treat missing as zero).
https://screamer.readthedocs.io/en/latest/ for the Python reference and full details.
x[t] - x[t-k], TA-Lib's MOM. Mathematically identical to Diff(k).