Indicators & Oscillators

Every indicator ever invented is the same trick: take the price and volume history you can already see, run it through arithmetic, and draw the result. That is not an insult. Good instruments make behavior visible. But it means no indicator contains information the chart didn't, and the trader who understands what each one measures will always beat the trader who collects them.

The taxonomy first

Overlays plot on the price chart itself, in price units: moving averages, bands, channels. Oscillatorsplot in their own pane on their own scale, usually bounded: RSI, Stochastic, MACD. Cutting across both: nearly everything islagging (built from completed candles), and the honest "leading" uses, divergence, exhaustion readings, are probabilities, never promises. Bounded oscillators travel between fixed limits, which is what makes "overbought" and "oversold" zones possible; unbounded ones, like MACD or OBV, wander freely.

Overlays worth knowing

Moving averages (SMA and EMA). The average close over the last N periods, redrawn each candle: trend, made visible. The simple version treats all periods equally; the exponential version leans toward recent ones. The famous 50 and 200 day averages matter partly because so many participants watch them, a self-fulfilling landmark. Price above a rising average is the definition most traders actually use for "uptrend."

VWAP. The volume-weighted average price of the session: the average entry of everyone who traded today. Institutions benchmark executions against it, which makes it one of the few lines the professionals genuinely watch. Price above VWAP means the average participant today is up; below, down.

Bollinger Bands. A moving average with bands a set number of standard deviations away. The bands breathe with volatility: squeezes mark quiet markets that often precede loud ones, and touches of a band are information about extension, not automatic signals to fade.

Keltner Channels and Donchian Channels. Cousins of the bands: Keltner builds its envelope from average true range, Donchian simply traces the highest high and lowest low of the last N periods. Donchian breakouts powered some of the most famous trend-following systems in history, which tells you how simple a working idea can be.

Parabolic SAR. Dots that trail a trend and flip sides when it bends. Designed as an always-in-the-market system, it shines in sustained trends and gets chopped to pieces in ranges; most modern use is as a trailing-stop reference rather than a standalone system.

Ichimoku Cloud. A complete Japanese system drawn as one overlay: dynamic support and resistance (the cloud), trend, momentum, and signal lines at once. It looks like weather radar the first week. Its virtue is forcing multiple confirmations into a single glance; its cost is that every element is still built from past price.

Pivot points. Reference levels computed from the prior period's high, low, and close. Watched heavily in futures and day trading, they are landmarks rather than predictions: places where reactions concentrate because everyone computed the same lines.

ATR (average true range). Not really an overlay or an oscillator: a volatility ruler. It answers "how far does this thing normally travel in a period?", which makes it the professional's tool for placing stops outside normal noise and for sizing positions in markets of different temperaments. Module 0's sizing math plus ATR is a complete stop-placement toolkit.

Oscillators worth knowing

RSI. The famous 0 to 100 momentum gauge: how strong have recent gains been relative to recent losses. Readings above 70 and below 30 get called overbought and oversold, but in a strong trend RSI can sit above 70 for weeks; the textbook fade works best in ranges. Its quieter superpower is divergence, covered below.

Stochastic (fast, slow) and StochRSI. Where did we close relative to the recent range? Closing near the highs of the range repeatedly is momentum; the oscillator just scores it 0 to 100. The slow version smooths the fast one's noise. StochRSI runs the stochastic math on RSI itself, momentum of momentum, twitchy by design, best for timing inside a trend you already trust.

Williams %R. The stochastic upside down, same question on an inverted scale. Pick one; owning both is owning the same gauge twice.

MACD. Two EMAs subtracted, plus a signal line and a histogram of their gap. It compresses trend and momentum into one pane: crossovers mark shifts, histogram shrinkage marks fading thrust. Unbounded, so "overbought" doesn't apply; divergence and crosses are the uses.

Rate of change and momentum. The plainest oscillators in existence: how far has price moved in N periods. No smoothing, no ceremony. Worth knowing because they make it obvious what every fancier momentum tool is elaborating on.

CCI. How far is price from its own recent average, scaled by typical deviation. Extreme readings mark stretched moves; like all stretch measures, "stretched" and "reversing" are different claims.

ADX. The odd one out: it measures trend strength, not direction. A rising ADX says a trend, either way, is strengthening; a low ADX says range. Its best job is telling you which of your other tools to trust today, trend tools in trends, fade tools in ranges.

Aroon. How recently did the highest high and lowest low occur? By measuring time since extremes rather than distance, it flags young trends early and identifies stalls, an underused perspective the momentum crowd forgets.

MFI. RSI with volume in the formula, "money flow." When price momentum and volume-weighted momentum disagree, someone is bluffing; MFI divergence is the tell.

CMF. Where inside each candle's range are closes happening, weighted by volume: accumulation near highs, distribution near lows, scored around zero. A pressure gauge more than a timing tool.

OBV and the A/D line. Running totals of volume, added on up periods and subtracted on down ones (OBV uses close-to-close direction; A/D weights by where the close landed in the range). Both exist to answer one question: is volume confirming the price move, or quietly voting against it?

Klinger. The deep cut: a volume-force oscillator run through EMAs, MACD's machinery applied to volume instead of price. Rarely plotted, occasionally illuminating, included here so the name never intimidates you.

Divergence, the honest version

Divergence is when price makes a new extreme and the oscillator refuses to confirm it: a higher high in price, a lower high in RSI. It means thrust is fading, and it is the closest thing oscillators have to a leading signal. It is also the most abused concept in technical analysis, because trends can print divergence for weeks while continuing. Divergence is a yellow light, never a green one: note it, then wait for price itself to turn and confirm.