GET/indicator/mass

Mass Index

Category: Momentum · Updated November 2026

The TAAPI.IO Mass Index API returns real-time and historical values for the Mass Index indicator as JSON, for crypto pairs and US stocks. Send an exchange, symbol and timeframe to get real-time or historical data, with no candles to download and no calculations to maintain.

Spec	Value
Endpoint	`GET https://v2.taapi.io/indicator/mass`
Outputs	`value`
Markets	Binance, Binance Futures, Bybit, Gate.io, Kraken and US stocks
Timeframes	`1m` to `1w`
Delivery	REST, bulk and WebSocket

Get Mass Index with one API call

This request returns Mass Index for BTCUSDT on 1-hour Binance candles. Add your API key to run it here.

curl -G https://v2.taapi.io/indicator/mass \
  -H "Authorization: Bearer YOUR_API_KEY" \
  --data-urlencode "exchange=binance" \
  --data-urlencode "symbol=BTCUSDT" \
  --data-urlencode "timeframe=1h"

import requests

resp = requests.get(
    'https://v2.taapi.io/indicator/mass',
    headers={'Authorization': 'Bearer YOUR_API_KEY'},
    params={'exchange': 'binance', 'symbol': 'BTCUSDT', 'timeframe': '1h'},
)
print(resp.json())

const params = new URLSearchParams({"exchange": "binance", "symbol": "BTCUSDT", "timeframe": "1h"});
const res = await fetch(`https://v2.taapi.io/indicator/mass?${params}`, {
  headers: { Authorization: 'Bearer YOUR_API_KEY' },
});
console.log(await res.json());

Mass Index API response

This response came from the live API on 9 November 2026. Long lists are shortened here.

200 OK

{
  "value": [18.513429685729328],
  "timestamp": [1794218400]
}

Field	Type	Description
`value`	number[]	Mass Index result
`timestamp`	integer[]	Unix time of each candle, in seconds

Mass Index API parameters

Name	Type	Required	Default	Description
`exchange`	string	Yes	—	`binance`, `binancefutures`, `bybit`, `gateio`, `kraken` or `stocks`
`symbol`	string	Yes	—	Pair or ticker, e.g. `BTCUSDT` or `AAPL`
`timeframe`	string	Yes	—	`1m` `5m` `15m` `1h` `4h` `1d` `1w`
`period`	number	No	—	Period
`results`	integer	No	1	Number of values to return, or `max`
`backtrack`	integer	No	0	Candles to skip from the most recent

What is Mass Index?

The Mass Index, developed by Donald Dorsey, looks for trend reversals by tracking the widening and narrowing of the high-low range. It does not use direction at all.

Mass Index formula

Output	Calculation
Ratio	EMA(high − low, 9) ÷ EMA(EMA(high − low, 9), 9)
Mass	Sum of the ratio over the period

How to read Mass Index in your code

Signal	Meaning	Condition
Reversal bulge	Range expansion then contraction	`value` rises above 27, then falls below 26.5

Limitations: The classic thresholds assume a 25-candle sum. A bulge also gives no direction, so another indicator must supply it. Nothing on this page is financial advice.

Compare the last two closed Mass Index values

Use backtrack=1 to skip the candle still forming, and results=2 to compare the last two closed candles. Arrays run oldest first.

curl -G https://v2.taapi.io/indicator/mass \
  -H "Authorization: Bearer YOUR_API_KEY" \
  --data-urlencode "exchange=binance" \
  --data-urlencode "symbol=BTCUSDT" \
  --data-urlencode "timeframe=1h" \
  --data-urlencode "results=2" \
  --data-urlencode "backtrack=1"

import requests

resp = requests.get(
    'https://v2.taapi.io/indicator/mass',
    headers={'Authorization': 'Bearer YOUR_API_KEY'},
    params={'exchange': 'binance', 'symbol': 'BTCUSDT', 'timeframe': '1h', 'results': 2, 'backtrack': 1},
)
data = resp.json()
prev, last = data['value']
print('value', prev, '->', last)
print('rising' if last > prev else 'falling or flat')

Get historical Mass Index values

Add results to return a series for backtesting or charting. The last element is the most recent candle.

curl -G https://v2.taapi.io/indicator/mass \
  -H "Authorization: Bearer YOUR_API_KEY" \
  --data-urlencode "exchange=binance" \
  --data-urlencode "symbol=BTCUSDT" \
  --data-urlencode "timeframe=1h" \
  --data-urlencode "results=100"

Get Mass Index for multiple symbols

Combine Mass Index with other indicators in one request. Each exchange, symbol and timeframe combination is one construct: Basic allows 1 per request, Pro 3 and Expert 10.

POST/bulk

curl -X POST https://v2.taapi.io/bulk \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "constructs": [
    {
      "id": "btc_1h",
      "exchange": "binance",
      "symbol": "BTCUSDT",
      "timeframe": "1h",
      "indicators": [
        {
          "id": "mass",
          "indicator": "mass"
        },
        {
          "id": "rsi",
          "indicator": "rsi"
        }
      ]
    }
  ]
}'

Stream Mass Index in real time

Subscribe over WebSocket to receive new values every 5 seconds while the candle is forming. Streaming supports 1m, 5m, 15m and 1h, and uses interval where REST uses timeframe.

WSSwss://v2.taapi.io/streaming

{
  "type": "subscribe",
  "id": "mass",
  "exchange": "binance",
  "symbol": "BTCUSDT",
  "interval": "1m",
  "indicator": "mass"
}

Mass Index API FAQ

What does the Mass Index API return?

It returns value, plus a timestamp for the request. Results are JSON.

Is the latest Mass Index value final?

No. The newest value belongs to the candle still forming and can change until it closes. Add backtrack=1 to read the last closed candle.

Which Mass Index settings can I change?

You can set period. See the parameters table above for defaults.

Can I get Mass Index for US stocks?

Yes. Use exchange=stocks with a ticker such as AAPL. US stocks are included on the Pro plan and above.

See the full list of indicators, or start for free.