Mean reversion is the theory suggesting that prices and returns eventually move back toward the mean or average. This mean or average can be the historical average of the price or return, or another relevant average such as the growth in the economy or the average return of an industry.
Read more: Mean Reversion Definition | Investopedia
https://www.investopedia.com/terms/m/meanreversion.asp
The Mean or Average could also be
VWAP or a
Pivot Point.
See also:
https://en.wikipedia.org/wiki/Mean_reversion_(finance)
https://www.dummies.com/how-to/content/how-to-trade-mean-reversion.html
https://investinganswers.com/financial-dictionary/economics/mean-reversion-94