MeasuresAverage gain versus average loss over a lookback window
Default windowFourteen intervals; shorter is noisier, longer lags
70 and 30Conventions, not rules — they fail persistently in trends
FBT Swap
What you should know
The relative strength index compares the average size of recent up moves to the average size of recent down moves, scaled to a range between zero and one hundred.
That is a description of momentum over a chosen window. Everything attached to it — overbought, oversold, divergence — is convention, and the conventions fail in exactly the conditions people most want to use them.
How it is calculated
Over a lookback period, typically fourteen intervals, the average gain and average loss are computed and expressed as a ratio. A high reading means up moves have dominated recently in magnitude; a low reading means the opposite.
The window is a choice. A shorter period makes it more reactive and noisier; a longer one smooths it and lags more.
Why 70 and 30 are not rules
Those thresholds are conventions from a specific market decades ago. There is nothing in the mathematics that makes them meaningful, and different assets and timeframes behave very differently around them.
In a strong trend an asset can hold above seventy for weeks. Selling the first touch is a well-documented way to exit early in exactly the moves worth holding.
Divergence and its limits
Divergence — price making a new high while RSI does not — is the most cited use. It describes a real thing: the latest move had less momentum behind it than the previous one.
It also occurs frequently in trends that continue, so as a standalone signal it produces many false readings. Context matters more than the indicator.
Using it honestly
It is useful as a description of current conditions alongside other information: has this move been unusually one-sided relative to the recent past? That question has an answer. "Is this a top?" does not.
FBT Swap shows RSI alongside other readings with its window stated and presents none of them as a trading instruction.
At a glance
At a glance
01
Measures
Average gain versus average loss over a lookback window
02
Default window
Fourteen intervals; shorter is noisier, longer lags
03
70 and 30
Conventions, not rules — they fail persistently in trends
04
Best use
Describing current conditions, not timing reversals
FAQ
Frequently asked questions
Clear answers before you decide.
Does RSI above 70 mean sell?+
No. It means recent up moves have outweighed down moves. In a strong trend this persists for extended periods, and acting on the first reading exits the move early.
What window should I use?+
Fourteen is the default and the most widely watched. Shorter windows react faster and generate more false readings; there is no window that makes the indicator predictive.
Is RSI useful at all?+
As one description of conditions among several, yes. As a standalone timing rule, published testing does not support it, and the honest framing is context rather than signal.
Risk notice
Crypto assets are volatile and on-chain transactions cannot be reversed. You can lose money, including all of it. Nothing here is financial advice.
