Moving averages tell you the direction. Oscillators like RSI and MACD tell you the speed — how much force is behind the move. And the single most useful thing they reveal is the moment that force starts to fade while price is still going. That disagreement is called divergence, and it's one of the earliest warnings a trend gives you.
Paint both on the chart above and follow along.
RSI, in plain terms
The Relative Strength Index measures how one-sided recent price action has been, on a 0–100 scale:
- Above 70 — buyers have been dominating; the move is "overbought." Not a sell signal by itself — strong trends stay overbought for a long time.
- Below 30 — sellers have dominated; "oversold." Again, not an auto-buy.
- The 50 line — an underrated tell. In an uptrend RSI tends to hold above 50 on pullbacks; in a downtrend it keeps failing below it.
The beginner mistake is treating 70/30 as buy/sell buttons. In a real trend they're not — price rips higher for weeks while RSI sits pinned above 70. Overbought means strong, not doomed.
MACD, in plain terms
MACD is two EMAs (12 and 26) subtracted from each other, plus a 9-period signal line on top. You don't need the math — read it as: the MACD line crossing above its signal line = momentum turning up; crossing below = turning down. The histogram (the bars) just shows the gap between them growing or shrinking, so shrinking bars mean the current push is running out of steam.
Divergence — the part that matters
Here's the payoff. Divergence is when price makes a new extreme but the oscillator doesn't.
- Bearish divergence: price grinds to a higher high, but RSI (or the MACD histogram) makes a lower high. Price went up; the force behind it went down. The rally is running on fumes.
- Bullish divergence: price stabs to a lower low, but the oscillator makes a higher low. Sellers pushed price lower but with less conviction each time — a bottom is often near.
Scroll the chart above to a major top and look at the RSI: you'll frequently see price making its highest high while RSI quietly makes a lower high. That's the market telling on itself.
Divergence is a warning, not a trigger. It says "this move is tiring," not "reverse right now." Trends can diverge for a long time before they actually turn — wait for price itself to confirm before you act.
Next: how to turn a read like this into an actual trade with a defined risk — because a signal you can't size is just an opinion.
In the lab
The 14-period RSI everyone quotes is just a default someone chose in 1978. See what the parameter actually does.
Open Indicators above the chart and drop RSI length from 14 to 7 — watch it turn twitchy, tagging overbought/oversold constantly. Push it to 28 — now it barely leaves the middle of the range. Neither is "right": faster settings fire earlier with more false alarms; slower ones fire late but rarely. The default is a compromise, not a law — and now you've seen why.