Absolute threshold
RSI(14) below 30 on the 1-hour close. Simple, and the one to start from — as long as you look at the firing history before believing it.
Screens
RSI on every pair,on the close,without you
Set the threshold and the interval once. It runs server-side against closed candles across your whole universe, and every firing is written down so you can judge the screen instead of remembering it.
What RSI actually measures, and where it misleads
It is a ratio of average gains to average losses
Over a look-back — 14 periods conventionally — RSI compares the average size of up moves to the average size of down moves and expresses it from 0 to 100. It is a momentum measure, not a valuation one: 25 does not mean cheap, it means the recent down moves have been larger and more frequent than the up ones.
Which is why 30 and 70 fail in a trend
The classic reading — buy under 30, sell over 70 — assumes the market returns to a middle. In a trending market RSI can sit above 70 for weeks while price doubles, and every "overbought" signal is a losing short. This is the single commonest way an RSI screen makes money in a backtest and loses it live: the backtest window happened to be range-bound.
So screen for RSI plus a regime
Pair the threshold with something that says whether the market is trending or ranging — ADX above or below a level, or a regime label with a long enough warm-up that it stops flipping. "RSI below 30" is a signal in a range and a warning in a downtrend, and only the second condition can tell you which one you are in.
And evaluate it on closed candles
RSI on a forming candle changes every tick and can cross your threshold and cross back before the bar ends. A screen that reads it fires on a value that never existed at the close. Everything here evaluates on closed candles by default — this was a real bug once, and closed-only is now the default rather than an option.
Ways to write it
With a trend filter
RSI below 30 AND ADX below 20 — oversold in a market that is actually ranging, rather than oversold on the way down.
As a rank
The ten lowest RSI values across the universe, rather than a fixed threshold that suits one market and not the next.
On the higher timeframe
Daily RSI as a condition on an hourly screen, so the entry timeframe and the context timeframe are not the same one.
Questions about RSI screening
What look-back should I use?
14 is the convention and a reasonable default. Shorter reacts faster and fires more; longer smooths and fires late. What matters more is that the same look-back is used in your screen and in any backtest of it, which it is here — both read the same computed series.
How often should it run?
On the close of the interval you are screening. Running an hourly RSI screen every five minutes gives you the same candle four extra times, and a per-symbol cooldown to stop it alerting on each.
Can I have the AI write it?
Yes — describe the condition and it drafts the specification, which you read and save. It drafts a filter, not a strategy, and enables nothing on your behalf.
Run one tonight
A paper account gets the whole screener — same schedules, same alert history, live data.