True Strength Index
The True Strength Index (TSI) is a momentum-based indicator developed by William Blau. The TSI is suitable for intraday time frames as well as long term trading and helps to define trend and oversold/overbought conditions.
The formula for TSI is:
TSI = ExpMovAvg(ExpMovAvg(NetChange, Long),Short) / ExpMovAvg(ExpMovAvg(AbsNetChange(n), Long),Short)
Long = Long Period
Short = Short Period
NetChange = Price - Price 1 bar ago
AbsNetChange = Absolute value of Price - Price 1 bar ago
XAVG(XAVG(C - C1, s), l) / XAVG(XAVG(ABS(C - C1), s), l) |
s =ShortPeriod, l =LongPeriod |
Where s
is the short period which must be an integer.
Where l
is the long period which must be an integer.
Examples
A True Strength Index 3, 9 can be written as follows.
XAVG(XAVG(C - C1, 3), 9) / XAVG(XAVG(ABS(C - C1), 3), 9)
![](https://media.screensteps.com/image_assets/assets/003/230/183/original/b8fc3cba-3087-434f-a223-50f40cef65d7.png)
![](https://media.screensteps.com/image_assets/assets/003/230/185/original/e062a369-a39e-40d0-af5e-65bb7a510b18.png)
Read more about True Strength Index (TSI) at Investopedia