Technical Indicators in Plain Language

Last reviewed on 2026-04-27.

Every ticker page includes a technical-analysis gauge that summarises a basket of indicators into a single rating — buy, sell, neutral, with finer "strong" variants on either end. That tile is convenient, and it is also a black box. This page opens the box: what the underlying indicators actually measure, how they are commonly read, and where they fail. The summary makes more sense once a reader knows what is being summarised.

What "technical" actually means

Technical indicators look at price and volume. That is all. They do not read filings, do not parse news, do not know what the company does. The premise — implicit in every technical study — is that price and volume already reflect what other market participants know, and that patterns in those two series carry information about supply and demand for the stock.

That premise is not free. Plenty of academic work has questioned whether technical indicators reliably predict future returns. The more honest reading is that they describe the current state of price action in compact, comparable terms. Whether that description happens to be useful depends on the stock, the timeframe, and how the indicator is combined with everything else.

Moving averages

The simplest indicator and arguably the most useful. A moving average smooths the price by averaging it over a window. A 50-day simple moving average (SMA) on a daily chart is the average closing price over the last fifty trading days, redrawn each day. An exponential moving average (EMA) does the same thing but weights recent days more heavily, so it reacts faster to new information.

How traders read them:

• Price above a long moving average (50-day, 200-day) is the textbook definition of "in an uptrend." Price below is the textbook definition of "in a downtrend."
• A short MA crossing above a long MA is the "golden cross," loosely associated with the start of an uptrend. The opposite, a "death cross," is the inverse.
• The slope of a moving average matters as much as price's position relative to it. A flat 200-day with price oscillating around it describes a sideways market; a rising 200-day with price holding above it describes a steady uptrend.

The catch: moving averages lag, by definition. They tell the reader what has been happening, smoothed. They are slow to register turning points and produce false signals in choppy, sideways markets where price keeps crossing back and forth.

Relative Strength Index (RSI)

An oscillator that compares the size of recent gains to the size of recent losses, expressed on a 0–100 scale. The standard window is 14 periods. The conventional reading: above 70 is "overbought", below 30 is "oversold."

Two important nuances:

• "Overbought" is not a sell signal. Strong uptrends can keep RSI pinned above 70 for weeks. Reading RSI as a contrarian signal in a strong trend is a recipe for selling early, repeatedly.
• RSI is more interesting when it diverges from price. Price making new highs while RSI makes lower highs is a "bearish divergence" — the rally is losing momentum even though the chart still looks strong. The opposite — falling price, rising RSI lows — is a "bullish divergence."

MACD

Moving Average Convergence Divergence. The MACD line is the difference between a fast EMA (typically 12 periods) and a slow EMA (typically 26). The signal line is a 9-period EMA of the MACD line itself. A histogram shows the gap between the two.

Traders watch three things:

• Crossovers. The MACD crossing above its signal line is a bullish trigger; crossing below is bearish. Like all crossover indicators, it works in trending markets and produces frequent false signals in flat ones.
• Zero line. MACD above zero means the fast EMA is above the slow EMA — a positive momentum bias. Below zero, the opposite.
• Histogram divergence. Same idea as RSI divergence: price making new extremes while the histogram does not is a sign of weakening momentum.

Bollinger Bands

A moving average with two channels drawn around it, typically two standard deviations of recent price away. Statistically, price spends most of the time inside the bands; pushes outside are unusual.

Common readings:

• The squeeze. When the bands narrow, volatility has compressed. A subsequent expansion often comes with a directional move — direction not specified by the bands themselves.
• Walking the band. In a strong trend, price can ride along the upper or lower band for many sessions. That is not a reversal signal.
• Mean reversion. In a sideways market, price touching one band and reverting toward the middle is the classic Bollinger pattern.

Volume-based indicators

Indicators built on volume rather than price. OBV (On-Balance Volume) adds up volume on up days and subtracts volume on down days, producing a running total that should track price in healthy moves and diverge in unhealthy ones. VWAP (Volume-Weighted Average Price) is intraday: the average price over the session, weighted by how many shares traded at each price. Institutional desks pay attention to VWAP because it benchmarks execution quality.

How the buy / sell / neutral gauge works

The technical-analysis widget on the ticker page does not run a single indicator. It evaluates a basket — typically a mix of moving averages and oscillators — across multiple timeframes and aggregates the results into a single rating. A "buy" rating means most of the underlying indicators are flashing buy by their conventional rule. A "strong buy" means almost all of them are.

This is where the convenience and the risk both come in. The convenience: a one-glance summary across many indicators at once. The risk: the summary collapses information. A "buy" rating that comes from twelve moving-average signals all triggering at once is one thing; a "buy" that comes from divergent oscillators and a missing trend signal is another. The summary cannot tell those apart.

The most honest way to use the gauge is as a check rather than an instruction. If the gauge says "strong buy" and the rest of the picture — fundamentals, news, sector context — points the same way, that is corroborating evidence. If it says "strong buy" while the company has missed its last three earnings reports, the disagreement is the more interesting signal.

Common mistakes

• Trusting any single indicator alone. Indicators rhyme; they do not repeat. A signal that worked spectacularly last cycle may misfire this one.
• Optimising parameters to historical data. A 27-period RSI that fits last year's chart perfectly is almost guaranteed to underperform a plain 14-period RSI going forward. Curve-fitting is real.
• Ignoring the timeframe. A "buy" on a 5-minute chart and a "sell" on a daily chart are not contradictions — they are answers to different questions.
• Treating technicals as a substitute for fundamentals. They are complementary readings of the same stock. The fundamentals primer covers the other half.

What technicals can and cannot do

Technicals are best at describing the current state of price action — trend or no trend, expanding or contracting volatility, healthy or weakening momentum. They are decent at framing entry and exit decisions for someone who has already decided what to trade and on what timeframe. They are poor at telling a reader what to trade in the first place; a screener pulled from the screener page filtered by fundamentals will narrow the universe more usefully than running technicals across the entire market.

For the chart conventions every indicator sits on top of — candlesticks, timeframes, gaps, volume — see how to read a stock chart. For how to combine technical and fundamental filters into a coherent screen, see the screener guide.

Nothing on this page is investment advice. See the disclaimer for the full position.