# Block Based CDD Chart Video Tutorial : So understand the Coin Days Destroyed (CDD) chart, let's first briefly explain how it's calculated. Which coin days are we talking about? Statistically, the importance of transfers for BTCs held for 155 days or more is now widely acknowledged by all on-chain analysts. This type of on-chain data is considered critical in Bitcoin trading.\ \ CDD is equal to the product of the Number of Days Held and the Amount of BTC Transferred.\ So, 1 BTC held for 12 years without any transfer has 4,380 days.\ If we calculate for 100 Bitcoin, 4,380 coin days would be destroyed.\ \ For instance: CDD=(Number of Days Held)×(Amount of BTC Transferred) 12 years = 4380 days CDD = 4380 x 100 = 438,000 coin days have been destroyed.\ \ \ So, how do we serve you with this on-chain metric? On the cddstamp.com platform, you can analyze two types of CDD metrics. The first is time-based CDD, and the second is block-based CDD. In this video, we'll introduce you to the more popular block-based CDD. In block-based CDD, we examine every Bitcoin movement block by block, categorizing each Bitcoin by its age group. This data is instantly displayed on your screen both graphically and in numerical form. You can visually see at what Bitcoin price the CDD data was triggered, allowing you to take financial precautions accordingly.
It even allows you to read some BTC hold data from the block anomaly monitor directly on the chart. If you're curious about the details of the transfers, the first thing you should do is note the block number that provides the CDD data and then analyze the activity within that block using Block Query.
In this area, you can find out whether the moving Bitcoins are going to miners, cold wallets, whales, derivatives or exchanges, large whales, or ETFs. You can track, block by block, exactly how much went in and how much went out, down to the finest details. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://cddstamp.gitbook.io/cddstamp/coin-days-destroyed-cdd/block-based-cdd-chart.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.