# Mean Coin Age

## Definition

Recall that the **coin-age model**
allows us at each given point in time to assign age to each coin/token.

There are two coin age defined metrics:

- Mean Coin Age - The average age of all coins/tokens on the blockchain.
- Mean Dollar Invested Age - The average age of all coins/tokens on the blockchain weighted by the purchase price.

### Example (Mean Coin age)

Given there are 100 tokens in existence:

- 50 of them have age 10 days
- 50 of them have age 20 days

then the average coin age is: (10 × 50 + 20 × 50) / 100 = 15 (coin-days)

### Example (Mean Dollar Invested Age)

Given there 100 tokens in existence:

- 50 of them have age 10 days and the token's price was $1 at that time
- 50 of them have age 20 days and the token's price was $2 at that time

then the mean dollar invested age is: (10 × 50 + 20 × 50) / (50 × $1 + 50 × $2) = 1500 / 150 = 10 (coin-dollar days)

More technical definition and computation description can be found here

## Access

## Measuring Unit

- Coin Age in Days
- Coin Dollar Age in Days

## Data Type

## Timebound

## Change Metrics

## Frequency

## Latency

## Available Assets

- Mean Coin Age is available for these assets
- Mean Dollar Invested Age is available for these assets

Note: timebound Mean Age metrics are available for these assets

## SanAPI

Available under the `mean_age`

and `mean_age_<timebound>`

names.

`1 2 3 4 5 6 7 8 9 10 11 12 13`

`{ getMetric(metric: "mean_age") { timeseriesData( slug: "santiment" from: "2020-01-13T00:00:00Z" to: "2020-01-18T00:00:00Z" interval: "1d" ) { datetime value } } }`

Available under the `mean_dollar_invested_age`

and
`mean_dollar_invested_age_<timebound>`

names.

`1 2 3 4 5 6 7 8 9 10 11 12 13`

`{ getMetric(metric: "mean_dollar_invested_age") { timeseriesData( slug: "santiment" from: "2020-01-13T00:00:00Z" to: "2020-01-18T00:00:00Z" interval: "1d" ) { datetime value } } }`