Moving Averages Explained (SMA and EMA)
A moving average smooths price data to show the trend. Learn how SMA and EMA are calculated, how traders use them in crypto and where they mislead.
A moving average is the average price of an asset over a set number of past periods, recalculated as each new period closes, so it "moves" along the chart and smooths out short-term noise. The simple moving average (SMA) weights every price equally, while the exponential moving average (EMA) gives more weight to recent prices so it reacts faster.
Moving averages are among the most widely used tools on crypto charts. They don't predict the future, but they make the direction and strength of a trend easier to see — and because so many traders watch the same lines, it helps to understand what they show and what they don't.
How a Simple Moving Average (SMA) Works
The SMA adds up closing prices over a number of periods and divides by that number.
Example — a 5-day SMA with these daily closes:
| Day | Close |
|---|---|
| 1 | 100 |
| 2 | 102 |
| 3 | 101 |
| 4 | 105 |
| 5 | 107 |
SMA = (100 + 102 + 101 + 105 + 107) ÷ 5 = 103.
On day 6, the oldest price (day 1) drops out and the new close is added. Because each price counts equally, a big move five days ago influences the SMA just as much as yesterday's close — and when it drops out of the window, the average can jump even if today's price barely changed.
How an Exponential Moving Average (EMA) Works
The EMA applies a weighting multiplier so that recent prices count more:
- Multiplier = 2 ÷ (number of periods + 1)
- EMA today = (today's close − yesterday's EMA) × multiplier + yesterday's EMA
For a 10-period EMA, the multiplier is 2 ÷ 11 ≈ 0.18, so today's price contributes about 18% of the new value. Older prices still count, but their influence fades gradually rather than dropping off a cliff.
The result is a line that hugs price more closely and turns earlier when the trend changes.
SMA vs EMA: Which to Use
| Feature | SMA | EMA |
|---|---|---|
| Weighting | Equal for all periods | More weight on recent prices |
| Reaction speed | Slower | Faster |
| False signals in choppy markets | Fewer | More |
| Smoothness | Smoother | Closer to price |
| Typical use | Long-term trend, widely watched levels (e.g. 200-day) | Shorter-term trend, momentum tools such as MACD |
Neither is objectively better. Many traders use an EMA for short timeframes and an SMA for long-term context. We cover this in more detail in Fundamental vs Technical Analysis in Crypto.
How Traders Use Moving Averages
1. Reading the trend
- Price above a rising average suggests an uptrend.
- Price below a falling average suggests a downtrend.
- A flat average with price crossing back and forth suggests no clear trend.
The 200-day SMA on Bitcoin's daily chart is one of the most widely cited long-term trend gauges.
2. Dynamic support and resistance
In trends, price often pulls back toward a moving average before continuing, so traders treat the line as a moving zone of support (in uptrends) or resistance (in downtrends). It's a zone, not a precise level. See support and resistance explained.
3. Crossovers
- Golden cross: a shorter average (commonly 50-day) crosses above a longer one (commonly 200-day).
- Death cross: the shorter average crosses below the longer one.
These get headlines, but they're lagging by design: by the time a 50-day average crosses a 200-day average, much of the move has already happened. If you want to go further, read Candlestick Patterns Every Beginner Should Know.
4. Building other indicators
Moving averages are the building blocks of other tools. MACD is based on the difference between two EMAs, and Bollinger Bands are built around an SMA.
Choosing Periods and Timeframes
There's no correct setting, but some conventions are useful to know because many traders watch the same lines:
| Period | Common use |
|---|---|
| 9–21 | Short-term momentum on intraday or daily charts |
| 50 | Medium-term trend on daily charts |
| 100 | Intermediate trend; less common |
| 200 | Long-term trend on daily charts; widely cited in market commentary |
On a weekly chart, longer averages (for example, a 200-week average) describe trends over years rather than months. Pick a timeframe that matches how long you intend to hold, and stick with it rather than switching settings to find a signal you like. For a deeper look, see RSI Explained.
Common Mistakes and Limitations
- 1Treating crossovers as buy or sell orders. In sideways markets, averages cross repeatedly, producing "whipsaws" that lose money on fees and small losses.
- 2Mixing timeframes. A 50-period average on an hourly chart covers about two days; on a daily chart it covers about seven weeks. Know which one you're looking at.
- 3Forgetting crypto trades 24/7. "Daily close" depends on the time zone the chart uses. Different sites can show slightly different averages.
- 4Optimizing settings on past data. Tweaking the period until it "worked" historically rarely holds up in the future.
- 5Ignoring liquidity. On thinly traded tokens, a few large trades can distort averages; they're far less meaningful than on major assets.
A Simple Checklist for Reading Moving Averages
- Which timeframe is the chart using?
- Is it an SMA or EMA, and how many periods?
- Is the average rising, falling or flat?
- Is price above or below it, and how far away?
- Does volume support the move? Our guide to volume analysis helps here.
- What would make you wrong, and how much are you willing to lose?
You can pull past prices from our historical data pages to see how averages behaved in earlier markets.
Bottom line
Moving averages turn noisy price data into a readable trend line. Use the SMA for steadier, long-term context and the EMA when you need faster reactions, but remember that both describe what has already happened. Treat them as one piece of evidence, combined with volume, key levels and sensible risk limits, rather than as signals to follow blindly.
Frequently asked questions
What is the difference between SMA and EMA?
A simple moving average (SMA) gives every price in the period equal weight. An exponential moving average (EMA) gives more weight to recent prices, so it reacts faster to new moves. The EMA turns sooner when the trend changes but also produces more false signals in choppy markets.
What does the 200-day moving average mean in crypto?
It is the average closing price over the last 200 days, widely watched as a gauge of the long-term trend. Price above a rising 200-day average is commonly read as a long-term uptrend, and below a falling one as a downtrend. It is a description of past prices, not a guarantee of what happens next.
What is a golden cross?
A golden cross occurs when a shorter moving average, commonly the 50-day, crosses above a longer one, commonly the 200-day. A death cross is the opposite. Both are lagging signals that confirm a change that has already happened, and they frequently produce false signals in sideways markets.
Which moving average is best for crypto?
There is no single best setting. Short averages such as 9, 20 or 21 periods suit short-term trend reading, while 50 and 200 periods are common for longer trends. Crypto trades around the clock, so check whether a chart uses daily closes and be consistent with the timeframe you choose.